Pinball info
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I mean to be helpful instead of questioning your ability, but when you replaced those MOSFETs did you check that all connections were correct by multimeter? The photo you posted has a couple of gotchas I've spotted:
See this link for testing the transistors with a multimeter - https://www.pinwiki.com/wiki/index....28SCR.29_or_Field_Effect_Transistor_.28FET.29
- Those MOSFETs are connected to ground via the components-side of the PCB, not the solder side - the solder-side for the ground pin connects to nowhere. If you've replaced those with a soldering iron and you didn't get enough solder dripping down through the hole to make the connection on the other side (and make it well!) or you didn't explicitly do that yourself by leaving yourself enough room on the legs to get an iron in, then you may have the ground pin floating.
- The traces on the solder-side for Q3 look incredibly suspiciously like the aforementioned ground pin is shorted to the signal line of the MOSFET.
See this link for testing the transistors with a multimeter - https://www.pinwiki.com/wiki/index....28SCR.29_or_Field_Effect_Transistor_.28FET.29
one of the mosfets likely still blown. test em with the board out for shorts. they’re static sensitive, so easy to put in a new one that goes short.
Good points, thanks. Yes, I did notice that - I've been peering at the board with a magnifying glass for some time.
If your coil is fooked you will continue to blow mosfets!
Also check diodes. Cant remember if they are on the coils or not
Also check diodes. Cant remember if they are on the coils or not
If a diode across one of the affected coils is shorted (and this is a very real possibility), it will destroy any new transistor in milliseconds - before your finger has even left the "power on" switch.
The very first, and probably MOST IMPORTANT thing to remember here is that fuses ARE NOT there to protect your equipment from damage. They are ONLY there to prevent faulty equipment from burning down your house! Fuses are mechanical devices and will not, and CAN NOT protect semiconductor devices from damage. If a fuse pops it will do so LONG after any semiconductor is destroyed.
Not throwing negative vibes here BUT not everyone is (or can ever be) an air force pilot, a dentist, candlestick maker or even ELECTRONIC TECHNICIAN.
Some things are best left to people with more knowledge in the area you need. Do you fix your own teeth?
If you wish to keep looking then do yourself a big favour and start at the beginning. I will talk about a single coil as the procedure is identical for one or 20.
******************************************
(1) Machine power off and armed with a multimeter and the knowledge to be able to use it and correctly interpret the results. Power stays OFF for this entire procedure.
(2) Cut one wire to the affected coil and check the diode across it (assuming there is a diode across the coil, AND there WILL be one somewhere even if it's on the PCB itself). You may also need to cut one end of the diode to make 100% certain it is OK or simply replace it as they are cents each (caution on the diode direction, observe the band or stripe on the cathode end).
(3) Replace the damaged or suspect transistor/MOSFET (with a suitable replacement or BETTER type) on the PCB and make 100% certain all of the connections are correct - this step is easy as you have lots of factory installed devices for comparison. Use short jumper wires to replace missing or damaged tracks (top and bottom of the PCB as required) and make 100% certain the new jumpers do not interfere with any adjacent tracks or pads.
(4) CLEAN the flux away from the damaged/newly repaired areas around the replaced parts - DO NOT SKIP THIS STEP - you might be surprised what a small amount of flux can hide from view!
(5) After repairs, using your meter again, confirm the replaced parts have similar readings ON ALL PINS to the ones around it that seem to be functioning correctly.
(6) ONLY AFTER completing all of the above steps is it 60% safe to switch the machine on, skipping any of the above is likely to end in tears.
*****************************************
If you are not comfortable doing any or all of the above it might be time to ask for someone else to look at the machine possibly before much more damage is done.
It is VERY easy to cause catastrophic damage in the blink of an eye if you are not sure of what you are doing.
Good luck with it whichever way you choose to go.
The very first, and probably MOST IMPORTANT thing to remember here is that fuses ARE NOT there to protect your equipment from damage. They are ONLY there to prevent faulty equipment from burning down your house! Fuses are mechanical devices and will not, and CAN NOT protect semiconductor devices from damage. If a fuse pops it will do so LONG after any semiconductor is destroyed.
Not throwing negative vibes here BUT not everyone is (or can ever be) an air force pilot, a dentist, candlestick maker or even ELECTRONIC TECHNICIAN.
Some things are best left to people with more knowledge in the area you need. Do you fix your own teeth?
If you wish to keep looking then do yourself a big favour and start at the beginning. I will talk about a single coil as the procedure is identical for one or 20.
******************************************
(1) Machine power off and armed with a multimeter and the knowledge to be able to use it and correctly interpret the results. Power stays OFF for this entire procedure.
(2) Cut one wire to the affected coil and check the diode across it (assuming there is a diode across the coil, AND there WILL be one somewhere even if it's on the PCB itself). You may also need to cut one end of the diode to make 100% certain it is OK or simply replace it as they are cents each (caution on the diode direction, observe the band or stripe on the cathode end).
(3) Replace the damaged or suspect transistor/MOSFET (with a suitable replacement or BETTER type) on the PCB and make 100% certain all of the connections are correct - this step is easy as you have lots of factory installed devices for comparison. Use short jumper wires to replace missing or damaged tracks (top and bottom of the PCB as required) and make 100% certain the new jumpers do not interfere with any adjacent tracks or pads.
(4) CLEAN the flux away from the damaged/newly repaired areas around the replaced parts - DO NOT SKIP THIS STEP - you might be surprised what a small amount of flux can hide from view!
(5) After repairs, using your meter again, confirm the replaced parts have similar readings ON ALL PINS to the ones around it that seem to be functioning correctly.
(6) ONLY AFTER completing all of the above steps is it 60% safe to switch the machine on, skipping any of the above is likely to end in tears.
*****************************************
If you are not comfortable doing any or all of the above it might be time to ask for someone else to look at the machine possibly before much more damage is done.
It is VERY easy to cause catastrophic damage in the blink of an eye if you are not sure of what you are doing.
Good luck with it whichever way you choose to go.
Fuses are only there to protect the wiring... if something breaks there can be a massive current inrush...
At the moment I've got coils 1 & 2 disconnected.
When I go through the coils test cycle under diagnostics, whilst pressing in both buttons inside the coin door, none seem to activate until #15.
4 to 7 inclusive, and 20 aren't used on this game, but a message appears on the DMD about #6.
When I go through the coils test cycle under diagnostics, whilst pressing in both buttons inside the coin door, none seem to activate until #15.
4 to 7 inclusive, and 20 aren't used on this game, but a message appears on the DMD about #6.
Attachments
I wouldn't be 'overthinking' the problem. Stick to the basics. The fault finding menus are often only a bit of a guide - nothing more.
