First post, by dulu
On the most popular Polish electronic forum, practically no meaningful answer can be obtained, if at least the electronics college has not finished. Here are lovers of old equipment themselves, so maybe you will be more understanding to me. At the same time, I think this gpu is worth repairing and taking the time.
- blank screen - I replaced the capacitors with 1000uF because I didn't have 1200uF on hand. The screen turned white
- I changed the capacitors to 1500uF - same symptoms
- I wiped the card thoroughly in IPA - the card started working
- the card worked properly in 3d mode for about 20 minutes. Thermal grease was replaced on the core and memories, the heat sink was quite cool. After 20 minutes there was a hang. I reset my computer, the card started showing artifacts although it still worked. After a while, she completely died. In the meantime, I changed the capacitors from 1500uF to 1000uF several times to make sure it was not their fault.
- I noticed that there is a short circuit on the capacitor I soldered (marked in the photo).
# from now on, I do not fully remember the sequence of my activities and insights, but I will try to explain it as clearly as I can
- when i removed the highlighted capacitor i was able to see POST again
- I tried to desolder the transistor marked in the picture and replace it with another one. I remember that the substitution worked, but I do not remember if it was not the fault that the capacitor was soldered out then; so let us consider this step to be insignificant. later i restored the original transistor and saw the post (without capacitor)
- when the capacitor was present and the transistor was not, regardless of which transistor pads I would connect with each other - there was always a short circuit. There is no short circuit when the capacitor is missing, which is probably related to the fact that without a capacitor I was able to see POST
- it's been a while and I have a blank screen even without a capacitor. I do not know if the card is completely dead or it is the fault of the fact that I am testing it on different equipment. There is a voltage of 0.43V across the transistor. I don't remember exactly, but when the card displayed POST, the voltage was definitely over 1V.
I have a multimeter. I can measure resistances, voltages and short circuits wherever you tell me. I plan to buy a hot-air station. If necessary, I will buy a working 8500LE or 9100 to have spare parts. At the same time, I am aware that apart from voltage problems, the gpu connections are damaged, but I will try to deal with it only when I can fix the problem with the wrong voltage.
here are links to two Russian articles that explain how the power supply of the card (specifically 8500le) is built. The Polish-Russian translator is not doing well and some words are incomprehensible to me.
https://radeon.ru/konkurs/8500le_upg.html
https://radeon.ru/konkurs/8500le_upg_2.html
I almost certainly forgot something important, so please ask if necessary. I will be grateful for any attempt to help.
