Fault finding guide

[RetroErik]

Hi, and thank for the 486SocketBlaster project.

I have tried making it. Here is a video about it. https://youtu.be/YV4V_aUYyPI Status is that three are now working, and 4 are not.

Could you point me in a direction on how to find the faults? I believe the problem is bad soldering or short circuit. Maybe this is impossible to fix. Maybe i could try putting the 486 Socket Blaster in the own at 250 digress Celcuis?

[scrapcomputing]

Thanks for the great video!

Soldering is indeed quite tricky because there is no room for error. What I did to avoid faults was to inspect closely each solder joint right after I solder one row, and fix any issues right away. Also using leaded solder + flux is probably the best option.

You may also check for continuity with the other side, as almost all pins are passed through, except for the power ones and the ones that connect to the headers (for multiplier etc.), though this can become very time consuming.

Not sure how you would fix a bad one. Wouldn't 250 degrees melt the plastics too? I would be curious to know if that fixes it :)

[RetroErik]

I tried baking it. Only made it worse. Now the PSU shuts down immediately after power on. But it helped adjusting the pins so that it more easily can go into the socket.

[scrapcomputing]

Good to know :)

I am experimenting with a new design that should be a lot easier to put together and debug. I will keep you posted.

[RetroErik]

Is it possible to use this socket? Or even better, do you know if its possible to buy ZIP Socket 3/7?

Looking forward to your next design.

[RetroErik]

Since you are working a new design. I have a couple of suggestions.

• A jumper so select internal or external Voltage Regulator. So i could keep the internal VR, but test with an external.
• A way to choose the CPU frequency - just like we do the Voltage. Or alt least have a series of jumper settings to choose 33, 40, 45 etc. MHz. Maybe this has to be done externally?

I don't see any problems doing VR and MHz adjustment externally. As long as we can connect wires we can always find room for it on the cabinet. Maybe even a 3D printer holder on top or on the side of the CPU.

Having a external VR og Mhz would give the ultimate overclocking tool.

[scrapcomputing]

You can't use such sockets in the current design because there is no way to solder the pins of the other.

Regarding the jumper for selecting the internal/external voltage regulator, this is not easy to do because it requires routing the voltage wires all the way to the outside and back inside again.

Selecting the FSB frequency is not possible, this is done by the motherboard. But I am planning on adding a pin for the Throttle Blaster which allows you to dial in the CPU performance.

[RetroErik]

Or course one cannot change FSB, but the frequence the CPU is running, or maybe the multiplier? E.x. 2.5x, 3x and 3.5x

Is not the Throttle Blaster only for reduce speed?, can it be used to "dial -in" frequency or clock multiplier?

[scrapcomputing]

You can only change the multiplier for DX4 an 5x86 just like with the CLKMUL jumper. These CPUs don't allow you to change it any further.

Yes, the Throttle Blaster will only reduce the speed. So what you can do is set the CPU to run at maximum speed, and then use the Throttle Blaster to dial in any "frequency" you want for speed-sensitive games. This works by doing pulse-width modulation on the STPCLK pin, which has a similar effect to reducing the frequency.

[RetroErik]

Thanks for the info. I follow you on Github and YouTube, looking forward to see it. If you need help beta testing or something just reach out.