Editing AMD Geode/Video 3/Script
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This is a work in progress textual description of the video. | |||
== Accessibility notice == | == Accessibility notice == | ||
Narrator: "A full textual description of this video is linked in the description below. Enjoy!" | Narrator: "Quick notice: A full textual description of this video is linked in the description below. Enjoy!" | ||
A glossy purple slide shows the text "A full textual description of this video is linked in the description below" | A glossy purple slide shows the text "A full textual description of this video is linked in the description below" | ||
== Recount == | == Recount == | ||
Narrator: "Welcome back to my AMD Geode repair video series. If you weren't here for the first few videos, let me give you a quick | Narrator: "Welcome back to my AMD Geode repair video series. If you weren't here for the first few videos, let me give you a quick recount." | ||
A glossy red slide shows the text "Welcome back! Now for a quick recap" | A glossy red slide shows the text "Welcome back! Now for a quick recap" | ||
Narrator: "In | Narrator: "In video 1 I bought and did some basic troubleshooting on an AMD Geode computer board. I drew some wrong conclusions and at the end damaged the board with bad soldering." | ||
Two scenes from part one are shown. The first is me using a bench power supply to power board. The second is a sticky mess of me soldering the board. The text "Part 1: Troubleshooting" is shown. | Two scenes from part one are shown. The first is me using a bench power supply to power board. The second is a sticky mess of me soldering the board. The text "Part 1: Troubleshooting" is shown. | ||
Narrator: "In | Narrator: "In video 2 I spent 6 hours trying to repair the board. I was successful in the end but damaged another part later." | ||
Two scenes from part two are shown. The first is soldering an inductor back on to the board. The second is running solder braid over the | Two scenes from part two are shown. The first is soldering an inductor back on to the board. The second is running solder braid over the network adapter with bent and ruined network pins. The text "Part 2: Repair" is shown. | ||
== Lessons learned == | == Lessons learned == | ||
Narrator: "Okay we're done. Let's talk about | Narrator: "Okay we're done. Let's talk about the lessons learned." | ||
A glossy green slide shows the text "Lessons learned" | A glossy green slide shows the text "Lessons learned" | ||
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* I didn't do these and failed | * I didn't do these and failed | ||
Narrator: "Secondly, understand the circuit properly! Had I done this I wouldn't have even had to solder the board." | Narrator: "Secondly, understand the circuit properly! Had I done this I wouldn't have even had to solder the board. Let me explain." | ||
A glossy orange slide shows the the following text: | A glossy orange slide shows the the following text: | ||
Line 38: | Line 40: | ||
* Lesson 2: | * Lesson 2: | ||
* Understand the circuit! | * Understand the circuit! | ||
* I could've avoided | * I could've avoided soldering altogether | ||
Narrator: " | Narrator: "In the video I drew this diagram" | ||
A picture of the circuit board near the CPU is shown. Text and lines are drawn over it, forming a diagram that shows: | A picture of the circuit board near the CPU is shown. Text and lines are drawn over it, forming a diagram that shows: | ||
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* From the 1.22 volt reference a 0.25 nanofarad capacitor and 10 kiloohm resistor in parallel run to DVREF | * From the 1.22 volt reference a 0.25 nanofarad capacitor and 10 kiloohm resistor in parallel run to DVREF | ||
* The 1.21 kiloohm resistor follows from the DVREF capacitor and resistor to the DRSET pin | * The 1.21 kiloohm resistor follows from the DVREF capacitor and resistor to the DRSET pin | ||
Narrator: "I | Narrator: "I also measured these voltages" | ||
The diagram is updated. DAVdd is marked as 3.3 volts, DVREF is 1.22 volts and DRSET is 40 millivolts | The diagram is updated. DAVdd is marked as 3.3 volts, DVREF is 1.22 volts and DRSET is 40 millivolts. | ||
Narrator: "How is DAVdd 3.3 volts if it's connected to a 1.2 volt reference?" | Narrator: "How is DAVdd 3.3 volts if it's connected to a 1.2 volt reference?" | ||
The voltage reference | The voltage reference is circled. | ||
Narrator: "How is DVREF 1.22 volts | Narrator: "How is DVREF 1.22 volts if there's a 10k resistor?" | ||
The 10k resistor is circled instead. | |||
Narrator: "What is this capacitor doing here?" | |||
The | The capacitor is circled instead. | ||
Narrator: "It makes no sense!" | Narrator: "It makes no sense!" | ||
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Three giant question marks are shown overlaid the diagram. | Three giant question marks are shown overlaid the diagram. | ||
Narrator: "When it comes to the part of the board I | Narrator: "When it comes to the part of the board I spend time troubleshooting and soldering, it gets worse!" | ||
A picture of the circuit board near is shown, near the VGA output port. It contains various surface mount chips, but in the center is a set of 3 small capacitors, 7 inductors, 3 ESD diodes and 7 resistors | A picture of the circuit board near is shown, near the VGA output port. It contains various surface mount chips, but in the center is a set of 3 small capacitors, 7 inductors, 3 ESD diodes and 7 resistors. | ||
Narrator: "I thought this circuit had the video signals travelling through capacitors, through inductors, through these ESD diodes, and out through these termination resistors." | Narrator: "I thought this circuit had the video signals travelling through capacitors, through inductors, through these ESD diodes, and out through these termination resistors." | ||
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Text overlays the diagrams labels the capacitors, inductors, ESD diodes and resistors. The top three capacitors are labelled R, G and B. Three separate lines from each of these capacitors draw through a set of inductors, ESD diodes and resistors. The lines are coloured red, green and blue. | Text overlays the diagrams labels the capacitors, inductors, ESD diodes and resistors. The top three capacitors are labelled R, G and B. Three separate lines from each of these capacitors draw through a set of inductors, ESD diodes and resistors. The lines are coloured red, green and blue. | ||
Narrator: "I figured that an ESD diode was faulty, pulling a signal line down to GND. This would | Narrator: "I figured that an ESD diode was faulty, pulling a signal line down to GND. This would be responsible for the low voltage." | ||
The text "Would a bad ESD diode pull the signal low?" is shown. The green line is replaced with a shorter line that ends at one of the pins of its ESD diode. | The text "Would a bad ESD diode pull the signal low?" is shown. The green line is replaced with a shorter line that ends at one of the pins of its ESD diode. | ||
Narrator: "Had I just measured the ESD | Narrator: "Had I just measured the ESD resistors with my multimeter in resistance and diode mode I could've ruled this out." | ||
A cartoon multimeter is shown with its black probe on the GND pin of the ESD diode and the red probe on the signal pin of the ESD diode. | A cartoon multimeter is shown with its black probe on the GND pin of the ESD diode and the red probe on the signal pin of the ESD diode. | ||
Narrator: "Even then, I decided to remove the capacitors to isolate the signals" | Narrator: "Even then, I decided to remove the capacitors to isolate the signals" | ||
The circuit board is shown again, this time with the top capacitors removed. The red, green and blue lines stop at the signal side of the capacitor and no longer flow to the inductors. | The circuit board is shown again, this time with the top capacitors removed. The red, green and blue lines stop at the signal side of the capacitor and no longer flow to the inductors. The text "I removed the capacitors to rule out any fault..." | ||
The text "I removed the capacitors to rule out any fault..." | |||
Narrator: "But these are connected to GND, not the signal!" | Narrator: "But these are connected to GND, not the signal!" | ||
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Narrator: "Removing them would not show the fault at all! I was doomed from the start." | Narrator: "Removing them would not show the fault at all! I was doomed from the start." | ||
The red, green and blue lines start again at the inductors and flow to the resistors again | The red, green and blue lines start again at the inductors and flow to the resistors again. | ||
== Writing code == | == Writing code == | ||
Narrator: "Without an obvious board issue, I | Narrator: "Without an obvious board issue, maybe I could find some hints in the chip itself?" | ||
A glossy blue slide shows the text "Investigating | A glossy blue slide shows the text "Investigating the chip" | ||
Narrator: "So I opened the | Narrator: "So I opened the data sheet and started looking for anything useful." | ||
The datasheet cover page is shown. An 'AMD Geode' logo is shown as well as the | The datasheet cover page is shown. An 'AMD Geode' logo is shown as well as the text "AMD Geode™ LX Processors Data Book" dated February 2009. | ||
Narrator: "I first looked at the at the video processor diagnostic register." | Narrator: "I first looked at the at the video processor diagnostic register." | ||
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Narrator: "I found some interesting fields that can be used to test the video processor DAC." | Narrator: "I found some interesting fields that can be used to test the video processor DAC." | ||
Three fields are shown in more detail. I will quote from the | Three fields are shown in more detail. I will quote from the data sheet here:<blockquote>Bits 27 to 20: DAC Test Value | ||
8-bit data value to drive to CRT DAC when selected by bit 19. | 8-bit data value to drive to CRT DAC when selected by bit 19. | ||
Line 152: | Line 151: | ||
The text "How to use DAC test mode:" is shown on screen. | The text "How to use DAC test mode:" is shown on screen. | ||
Narrator: "Don't. Save yourself | Narrator: "Don't. Save yourself. This is a nightmare of problems." | ||
The single word "Don't" is shown in the center of the screen. | The single word "Don't" is shown in the center of the screen. | ||
Line 160: | Line 159: | ||
The three fields are shown again, with the "MBD_MSR_DIAG" register circled. | The three fields are shown again, with the "MBD_MSR_DIAG" register circled. | ||
Narrator: "I googled it | Narrator: "I googled it, it only has three results" | ||
Top of a google results page is shown. It says there are about 3 results. | Top of a google results page is shown. It says there are about 3 results. | ||
Line 166: | Line 165: | ||
Google helpfully says "It looks like there aren't many great matches for your search" | Google helpfully says "It looks like there aren't many great matches for your search" | ||
The text "Google | The text "Google knows 3 results:" is shown on screen. | ||
Narrator: "The top one is my website!" | Narrator: "The top one is my website!" | ||
Line 178: | Line 177: | ||
The text "The top result is my website!" is shown on screen. | The text "The top result is my website!" is shown on screen. | ||
Narrator: "It's | Narrator: "It's probably a typo for GLD_MSR_DIAG." | ||
The GLD Diagnostic MSR register is shown, named GLD_MSR_DIAG. | The GLD Diagnostic MSR register is shown, named GLD_MSR_DIAG. | ||
Line 186: | Line 185: | ||
The text "Maybe it meant GLD_MSR_DIAG?" is shown on screen. | The text "Maybe it meant GLD_MSR_DIAG?" is shown on screen. | ||
Narrator: "But that | Narrator: "But that makes no sense! It's reserved for AMD!" | ||
The note about it being reserved is circled. | The note about it being reserved is circled. | ||
Line 192: | Line 191: | ||
The text "But it's reserved and not for use?" | The text "But it's reserved and not for use?" | ||
Narrator: "Maybe it's a typo for the reserved | Narrator: "Maybe it's a typo for the reserved field I saw earlier?" | ||
The three diagnostic fields from earlier are shown. The RSVD field is circled. | The three diagnostic fields from earlier are shown. The RSVD field is circled. | ||
Line 208: | Line 207: | ||
The text "The bit fields both match" is shown on screen. | The text "The bit fields both match" is shown on screen. | ||
Narrator: " | Narrator: "I went to set the registers and found it's a mix of MSRs and memory mapping." | ||
The VP Diagnostic MSR (MSG_DIAG_VP) and Video Processor Test Mode (VTM) registers are shown. | The VP Diagnostic MSR (MSG_DIAG_VP) and Video Processor Test Mode (VTM) registers are shown. | ||
Line 218: | Line 217: | ||
The text "They use a mix of MSRs and memory mapping?" is shown on screen. | The text "They use a mix of MSRs and memory mapping?" is shown on screen. | ||
Narrator: "The documentation on how to use these is fairly confusing" | Narrator: "The documentation on how to use these is fairly confusing." | ||
Excerpts from the GeodeLink datasheet section are shown, including Table 4-2. MSR Mapping and the Memory and I/O Mapping section. Both have a lot of complicated wording and require further context to understand. | Excerpts from the GeodeLink datasheet section are shown, including Table 4-2. MSR Mapping and the Memory and I/O Mapping section. Both have a lot of complicated wording and require further context to understand. | ||
Narrator: "I gave up and just edited the Linux driver to set registers for me." | |||
Narrator: " | |||
The following source code is shown: | The following source code is shown: | ||
Line 257: | Line 254: | ||
Narrator: "Changing it didn't help." | Narrator: "Changing it didn't help." | ||
The text " | The text "Unfortunately not" appears on the screen. | ||
Narrator: " | Narrator: "I did find some DAC power registers." | ||
The MISC register is partially shown. The following fields are shown:<blockquote>Bits 63 to 13: RSVD (RO) | The MISC register is partially shown. The following fields are shown:<blockquote>Bits 63 to 13: RSVD (RO) | ||
Line 290: | Line 287: | ||
</blockquote>The text "Maybe the DAC is powered down?" is shown on screen. | </blockquote>The text "Maybe the DAC is powered down?" is shown on screen. | ||
Narrator: "But I confirmed these were set properly" | Narrator: "But I confirmed these were set properly." | ||
The text "Nope, these are set fine" appears on the screen. | The text "Nope, these are set fine" appears on the screen. | ||
Line 333: | Line 330: | ||
</blockquote>The text "I found the GLCP_DAC register" is shown on screen. | </blockquote>The text "I found the GLCP_DAC register" is shown on screen. | ||
Narrator: "It has fields showing the | Narrator: "It has fields showing the output voltage" | ||
The status registers are circled. | The status registers are circled. | ||
The text "It reports on DAC output | The text "It reports on the DAC output" is shown on screen. | ||
Narrator: "It correctly reports the output as being low voltage" | Narrator: "It correctly reports the output as being low voltage" | ||
The text " | The text "Correctly reports low voltage" appears on screen. | ||
Narrator: "Well, that wasn't too helpful." | Narrator: "Well, that wasn't too helpful." | ||
Line 354: | Line 351: | ||
A microscope photo from above showing the same DAC VREF circuit from before. | A microscope photo from above showing the same DAC VREF circuit from before. | ||
Narrator: "Here's the components labelled again." | Narrator: "Here's the components labelled again." | ||
Line 366: | Line 361: | ||
* The 1.2v voltage reference | * The 1.2v voltage reference | ||
Narrator: "and here are the signal lines labelled correctly:" | |||
Narrator: "and here are the signal lines labelled correctly" | |||
Five lines are drawn over PCB tracks. These connect: | Five lines are drawn over PCB tracks. These connect: | ||
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* The 1.2v VREF between DVREF and GND | * The 1.2v VREF between DVREF and GND | ||
* The 10k resistor between DVREF and 3.3v | * The 10k resistor between DVREF and 3.3v | ||
Narrator: "For now let's focus on the DVREF line." | Narrator: "For now let's focus on the DVREF line." | ||
Line 391: | Line 382: | ||
The text "DVREF measures 1.2V" is shown on screen. | The text "DVREF measures 1.2V" is shown on screen. | ||
Narrator: "Linux drops it to 0.8 volts!" | Narrator: "Linux booting drops it to 0.8 volts!" | ||
The Linux mascot is shown in the corner on screen. The mascot is [[commons:File:NewTux.svg|NewTux]], created by [mailto:lewing@isc.tamu.edu Larry Ewing] using [https://www.gimp.org/ The GIMP] and turned in to a slick vector by [https://www.opendesktop.org/p/1082435 gg3po]. | |||
The text "Linux drops it to 0.8V!" in shown on screen. | The text "Linux drops it to 0.8V!" in shown on screen. | ||
Line 405: | Line 398: | ||
The multimeter measures between GND and the 3.3v rail. | The multimeter measures between GND and the 3.3v rail. | ||
The text "3.3V rail is 0. | The text "3.3V rail is 0.8V?" is shown on screen. | ||
Narrator: "As a quick check I bridged the 3.3 volt rail to a nearby working rail" | Narrator: "As a quick check I bridged the 3.3 volt rail to a nearby working rail" | ||
Line 425: | Line 418: | ||
nel 5.16.0-rc2+ on an i586 (dev/tty1) | nel 5.16.0-rc2+ on an i586 (dev/tty1) | ||
alhost login:</blockquote>The | alhost login:</blockquote>The camera briefly zooms out and shows an orange frog squeeze doll on its back. There's a hole on its underside that makes it look like a gaping butt hole. | ||
I didn't need to text describe that but I did. I also can't fix it because I filmed it over a year ago. | |||
Narrator: "I checked the other side of the board and found this:" | Narrator: "I checked the other side of the board and found this:" | ||
Line 443: | Line 436: | ||
The resistor is marked 01Y, meaning 1 ohm! | The resistor is marked 01Y, meaning 1 ohm! | ||
The text "Blown resistor!" is shown on screen. | The text "Blown 1Ω resistor!" is shown on screen. | ||
Narrator: "And a yellowed capacitor!" | Narrator: "And a yellowed capacitor!" | ||
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The view zooms in on the capacitor. | The view zooms in on the capacitor. | ||
The text " | The text "Yellow capacitor!" is shown on screen. | ||
==Repair== | ==Repair== | ||
Narrator: "Time to finally repair something" | Narrator: "Time to finally repair something" | ||
A glossy | A glossy yellow slide shows the text "Repair time!" | ||
Narrator: "I used my soldering iron to remove the nearby capacitor and the resistor." | Narrator: "I used my soldering iron to remove the nearby capacitor and the resistor." | ||
Line 462: | Line 455: | ||
Tweezers hold the yellowed capacitor while a large square soldering iron touches its side. | Tweezers hold the yellowed capacitor while a large square soldering iron touches its side. | ||
Narrator: "I heated up one side of each component and forced that end away from its pad" | |||
The solder on the capacitor melts on one side and the tweezers pull the component to stand up. | |||
The | The iron then melts one side of the resistor while holding it with the tweezers. | ||
The | The resistor slips and bends sideways, disconnecting from the opposite pad. | ||
A part of capacitor remains on the pad. | |||
Narrator: "Then | Narrator: "Then heated the other side up and pulled the component away" | ||
The iron melts the resistor's pad again and the tweezers pull it away. | The iron melts the resistor's pad again and the tweezers pull it away. | ||
Line 484: | Line 477: | ||
The soldering heats up both resistor pads and cool to hold a small wire in place to bridge them. | The soldering heats up both resistor pads and cool to hold a small wire in place to bridge them. | ||
Narrator: "Then | Narrator: "Then cleaned up the soldering mess" | ||
A cotton | A cotton tip is used to remove all the soldering flux from the board. | ||
The board is | The board is shown post-clean. | ||
Narrator: "Do not do this!" | Narrator: "Do not do this!" | ||
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The text "Should I have removed both?" is shown. | The text "Should I have removed both?" is shown. | ||
Narrator: " | Narrator: "Finding a suspicious voltage drop could have identified the bad component". | ||
A multimeter is shown probing either side of the blown resistor. | A multimeter is shown probing either side of the blown resistor. | ||
The text "Measuring voltage drop would show | The text "Measuring voltage drop would show the problem component" is shown. | ||
Narrator: "Secondly, I removed the components wrong" | Narrator: "Secondly, I removed the components wrong" | ||
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An orange cartoon resistor sits on a an abstract blue circuit board. | An orange cartoon resistor sits on a an abstract blue circuit board. | ||
The text "I | The text "I removed components wrong" is shown. | ||
Narrator: "I forced heat through one end of the component" | Narrator: "I forced heat through one end of the component" | ||
Line 540: | Line 533: | ||
The resistor is now completely gone from the board, with the board and pads still hot. | The resistor is now completely gone from the board, with the board and pads still hot. | ||
The text "Then tweezers | The text "Then tweezers for removal" is shown. | ||
Narrator: "This fixed the brightness, but not the original issue" | Narrator: "This fixed the brightness, but not the original issue" | ||
A glossy | A glossy yellow slide shows the text "This didn't fix the original issue" | ||
== BIOS editing == | == BIOS editing == | ||
Narrator: "Okay, Linux works. Maybe the BIOS is broken?" | Narrator: "Okay, Linux works. Maybe the BIOS is broken?" | ||
- show modbin6 menu 'i opened the bios in modbin6, a bios editor' | |||
- show output display 'i checked the default output display option' | |||
- circle crt 'it is set to CRT, which means VGA' | |||
- 'i tried re-flashing BIOS anyway' | |||
- 'but i think awdflash requires a video display' | |||
- 'even then, i risk bricking my bios' | |||
- 'i bought some BIOS chips just in case' | |||
== Ethernet removal == | == Ethernet removal == | ||
- pins missing, confusion about IRDYB | |||
- hot air 40 mins | |||
- testing on stuff | |||
- melted the clock connector | |||
== BIOS flashing == | == BIOS flashing == | ||
- months later? (check wiki) | |||
- ram didn't detect well | |||
- debian 12 | |||
- flashrom, hot swapping | |||
- different bioses had no change | |||
- ram broke again | |||
- good ram made it work? | |||
==Conclusion== | |||
- TODO | |||
- credits | |||
[[Category:Projects]] | [[Category:Projects]] |