My Compaq SLT 286 worked. The powersupply was broken (the Riva caps), but I charged the battery with my bench powersupply and I could run the laptop.
I fixed the powersupply by replacing the Riva caps and the laptop worked. Except the harddisk was failing.
So I opend the laptop and disconnected the harddisk, tried it in an old pc and it made the pc hang on post (couldn't even enter the bios). So HDD is broken
After that I just didn't place the HDD back and I tested the system while it was disasembled and the lights etc worked and every thing worked.
I found a boot diskette and tried to boot via disk (1.44mb). But didn't work. I stupidly FORGOT (it was late) it won't work (needs to be 720kb) because the Dallas clock battery is flat. So without thinking like a normal person I thought the diskdrive was broken.
So I grabbed another diskdrive but found out the connector is different. So my brilliant idea was to swap the head of the diskdrive. I swapped and ofcourse it didn't work (again bios was not set because of Dallas clock).
While the system was on I pulled out the diskdrive cable and the laptop gave an IO error (duh). So I put the cable back in and I had no IO error.. Everything was disasembled and hanging around the case.
Rebooted mutiple times, and all of a sudden the laptop turned off...And it was dead. The powerbrick light also went out. So I turned off the laptop (I mean the switch on the laptop/internal powersupply), pulled out the powercable and put in the power cable again. Turned the switch to on and the powersupply light worked again (green light). But nothing on the laptop. No LED , nothing.
I checked the pins on the battery connection of the internal powersupply and it is 17.something volts (far left + far right -). I opened the internal powersupply and checked the caps. Only the first cap (C510) had voltage in it (when connected to power) the voltage is 17.something. The other caps don't have any charge at all (so meaning C511 , that one above that , and the others C503 and C504, all have zero volts).
Desoldered the big ones and measured them and they are fine (0.9% pretty good). So I soldered them back and checked the output.. Well I think the output isn't good. I measured the 17.something volts on pin 15 and on antoher pin I measured about 8 volts (Pin 5 or 7) (I don't know exactly I measured it 7 hours ago and this is just on top of my head, lol).
I checked with thermal camera and the first diode (CR502) on the internal powersupply heats up a bit, but not that much about 45C. I desoldered that one and measured it and it's fine..
I also measured on the mainboard(motherboard) and I can't find any voltage, just 1 time 17.something volts on a cap behind the connector. I can't follow the board layout with the eye.. (complicated it goes from front to back to front to back).
I also found 1 diode(C504) somewhere near the power connector on the right side (on the motherboard), where the + side is shorted to ground, but the - side isn't shorted to ground . All other diodes on the motherboard (on the front) only short to ground on the ground side and not on the + side) so that confused me. But maybe it's a minus powerrail or something (I don't have that much knowledge about electronics).
But I think the problem is with the internal powersupply. (Doesn't work on battery anymore and also not working when benchpowersupply to the terminals)
Is it correct that only C510 has voltage in it when it's connected to power? Or do the other caps also supposed to have voltage in them?
Anybody know the pinout of the connector on the internet powersupply? What voltage on wich pin?
If someone has any ideas or input on this matter it would be highly appreciated
I hope this laptop can be brought back to life. This laptop has emotional value to me (I inherited it when my dad passed away). I remember me as a small child playing on this laptop...
PS: I apologize for the rather chaotic post. It was all from memory + I'm not English
I fixed the powersupply by replacing the Riva caps and the laptop worked. Except the harddisk was failing.
So I opend the laptop and disconnected the harddisk, tried it in an old pc and it made the pc hang on post (couldn't even enter the bios). So HDD is broken
After that I just didn't place the HDD back and I tested the system while it was disasembled and the lights etc worked and every thing worked.
I found a boot diskette and tried to boot via disk (1.44mb). But didn't work. I stupidly FORGOT (it was late) it won't work (needs to be 720kb) because the Dallas clock battery is flat. So without thinking like a normal person I thought the diskdrive was broken.
So I grabbed another diskdrive but found out the connector is different. So my brilliant idea was to swap the head of the diskdrive. I swapped and ofcourse it didn't work (again bios was not set because of Dallas clock).
While the system was on I pulled out the diskdrive cable and the laptop gave an IO error (duh). So I put the cable back in and I had no IO error.. Everything was disasembled and hanging around the case.
Rebooted mutiple times, and all of a sudden the laptop turned off...And it was dead. The powerbrick light also went out. So I turned off the laptop (I mean the switch on the laptop/internal powersupply), pulled out the powercable and put in the power cable again. Turned the switch to on and the powersupply light worked again (green light). But nothing on the laptop. No LED , nothing.
I checked the pins on the battery connection of the internal powersupply and it is 17.something volts (far left + far right -). I opened the internal powersupply and checked the caps. Only the first cap (C510) had voltage in it (when connected to power) the voltage is 17.something. The other caps don't have any charge at all (so meaning C511 , that one above that , and the others C503 and C504, all have zero volts).
Desoldered the big ones and measured them and they are fine (0.9% pretty good). So I soldered them back and checked the output.. Well I think the output isn't good. I measured the 17.something volts on pin 15 and on antoher pin I measured about 8 volts (Pin 5 or 7) (I don't know exactly I measured it 7 hours ago and this is just on top of my head, lol).
I checked with thermal camera and the first diode (CR502) on the internal powersupply heats up a bit, but not that much about 45C. I desoldered that one and measured it and it's fine..
I also measured on the mainboard(motherboard) and I can't find any voltage, just 1 time 17.something volts on a cap behind the connector. I can't follow the board layout with the eye.. (complicated it goes from front to back to front to back).
I also found 1 diode(C504) somewhere near the power connector on the right side (on the motherboard), where the + side is shorted to ground, but the - side isn't shorted to ground . All other diodes on the motherboard (on the front) only short to ground on the ground side and not on the + side) so that confused me. But maybe it's a minus powerrail or something (I don't have that much knowledge about electronics).
But I think the problem is with the internal powersupply. (Doesn't work on battery anymore and also not working when benchpowersupply to the terminals)
Is it correct that only C510 has voltage in it when it's connected to power? Or do the other caps also supposed to have voltage in them?
Anybody know the pinout of the connector on the internet powersupply? What voltage on wich pin?
If someone has any ideas or input on this matter it would be highly appreciated
I hope this laptop can be brought back to life. This laptop has emotional value to me (I inherited it when my dad passed away). I remember me as a small child playing on this laptop...
PS: I apologize for the rather chaotic post. It was all from memory + I'm not English
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