Irem PCBs and leaking capacitors - M92/M107

[system11]

Well you can do it with a normal iron (still need a fine tip) and a mechanical cheap solder sucker, but you'll struggle with cleaning out some of the holes if there's corrosion.

[Green beret]

Well you can do it with a normal iron (still need a fine tip) and a mechanical cheap solder sucker, but you'll struggle with cleaning out some of the holes if there's corrosion.

My solder station is good but I don't have very pointed tip. I need a good solder sucker. I will post a pic with what I have later tonight.

[Green beret]

Here it is what I have:
https://imageshack.com/i/eyeKBtPTj

[rtw]

As has been pointed out earlier it is difficult to desolder through-hole componenets which are connected to a ground plane or power plane. The reason being that the heat is dissipated through the plane.

If you use more heat you run the risk of delaminating the PCB or destroying the pad.

The solution is called: Bismuth

Bismuth is an element which when mixed with tin will create an alloy which melts at a much lower temperature than normal lead/tin alloys.

First you need some of this:

http://www.chipquik.com/store/product_i ... _id=210001

This is the lead version, very few arcade PCBs were made with lead-free alloys so we will stick with lead.

Before working on your precious PCB it's a good
idea to practice on a junk PCB.

Here is a rough outline of how to do it.

Code: Select all

. Cut off the component leaving the leg

. Apply the special flux from the ChipQuik package on the solder joint

. Apply the ChipQuik on the solder joint. The idea here is to mix the bismuth into the joint thus creating a joint with lower temperature.

. Sometimes it is better to remove excess solder from the joint with a solder-wick before you start with the ChipQuik.

. When the joint is saturated the temperature should be low enough to usa pair of tweezers to gently lift out the leg.

. Then use a solder-wick to remove excess solder from the hole.

. If you have managed to saturate the joint with ChipQuik you can sometimes "tap" the PCB and the solder will drop out of the hole.

The advantage of using this technique is that you are working at a much lower temperature so you do not risk delaminating your PCB.

Note:
When using a solder-wick do not use the end of the wick, Instead leave 2 cm's from the end. In this fashion the solder will melt into both sides of the wick.

[Green beret]

As has been pointed out earlier it is difficult to desolder through-hole componenets which are connected to a ground plane or power plane. The reason being that the heat is dissipated through the plane.

If you use more heat you run the risk of delaminating the PCB or destroying the pad.

The solution is called: Bismuth

Bismuth is an element which when mixed with tin will create an alloy which melts at a much lower temperature than normal lead/tin alloys.

First you need some of this:

http://www.chipquik.com/store/product_i ... _id=210001

This is the lead version, very few arcade PCBs were made with lead-free alloys so we will stick with lead.

Before working on your precious PCB it's a good
idea to practice on a junk PCB.

Here is a rough outline of how to do it.

Code: Select all

. Cut off the component leaving the leg

. Apply the special flux from the ChipQuik package on the solder joint

. Apply the ChipQuik on the solder joint. The idea here is to mix the bismuth into the joint thus creating a joint with lower temperature.

. Sometimes it is better to remove excess solder from the joint with a solder-wick before you start with the ChipQuik.

. When the joint is saturated the temperature should be low enough to usa pair of tweezers to gently lift out the leg.

. Then use a solder-wick to remove excess solder from the hole.

. If you have managed to saturate the joint with ChipQuik you can sometimes "tap" the PCB and the solder will drop out of the hole.

The advantage of using this technique is that you are working at a much lower temperature so you do not risk delaminating your PCB.

Note:
When using a solder-wick do not use the end of the wick, Instead leave 2 cm's from the end. In this fashion the solder will melt into both sides of the wick.

Hi,
Thanks again for your help.
So I need to buy ChilQuik and follow the instructions? Your instructions are simple enough for me to understand.
I need to buy thus "Bismuth" too?
My local expert agreed to recap each board for 20€. He already recapped one. 3 to go = 60€.
Do you think it is very expensive?

[rtw]

So I need to buy ChilQuik and follow the instructions? Your instructions are simple enough for me to understand.
I need to buy thus "Bismuth" too?
My local expert agreed to recap each board for 20€. He already recapped one. 3 to go = 60€.
Do you think it is very expensive?

ChipQuik contains bismuth so you only need to buy this:

http://www.chipquik.com/store/product_i ... _id=210001

Current price is 16 USD per pack and then you need to get it shipped. If you have access to Farnell you can buy it from there as well.

[Green beret]

So I need to buy ChilQuik and follow the instructions? Your instructions are simple enough for me to understand.
I need to buy thus "Bismuth" too?
My local expert agreed to recap each board for 20€. He already recapped one. 3 to go = 60€.
Do you think it is very expensive?

ChipQuik contains bismuth so you only need to buy this:

http://www.chipquik.com/store/product_i ... _id=210001

Current price is 16 USD per pack and then you need to get it shipped. If you have access to Farnell you can buy it from there as well.

This is great! I will buy it and will let you know how it went!
Thanks for all rtw!

[markedkiller78]

4 years later bump

I picked up a brown cap In The Hunt M92 late last year. Thankfully none of the caps have leaked.

Thanks for the heads up and cap list. I’ve just replaced mine and I’m guessing, mixed a cap or 13 up. Do these caps cover the sound as I’ve got very loud SFX or very low BGM now.

I’ll double check all the locations. I bought a mix of Panasonic and Nichon caps from RS-Service. The only deviation, were the 1uF 50V, I had to get 85c or
Wait 3 months for 105c. Is there any chance that’s the problem?

[Sumez]

Thanks for bumping this thread, as I haven't noticed it before.

I have both an M92 and an M97 board lying around, I'll have to go through them.

[markedkiller78]

Hmm, I’m starting to think the sound mix is garbage on this game. The SFX are much louder than the BGM on the YT videos I’ve checked