I pulled this for a cap kit and noticed that the part in location TH501 is cracked and quite possibly bad. A local friend had the same problem on his k4900 chassis (very similar to this) and he couldn't find a replacement and ended up harvesting one from a parts k4900 chassis. Help please! I need a new part!
WG K5500 chassis TH501 replacement part?
- Thread starter ifkz
- Start date
Oryk Zinyo
Well-known member
Is it marked in any way, such as color bands? I found this site and if it has markings on it they should be able to get you a replacement part...
http://www.koaspeer.com/resistors.asp?part=45
http://www.koaspeer.com/resistors.asp?part=45
It is a thermistor. It's what controls the degaussing coil. They usually look like hell (outer shell a cracked and falling apart), but work fine.
Edward
KenLayton
In Memoriam
MCM Electronics has both common degausser controls:
# 33-650 Globar Thermistor
# 32-7120 Thermistor Posistor
# 33-650 Globar Thermistor
# 32-7120 Thermistor Posistor
OP
OP
ifkz
Well-known member
Thanks guys. I doubt the part has anything to do with the odd geometry I'm seeing now that I know what function it performs. This information is good to know. Now onto the next step: figuring out what caps this monitor should have on it and if any of the mods on the solder side are factory or operator upgrades.
KenLayton
In Memoriam
In general, the components you see soldered to the solder side of the main board are Wells-Gardner "undocumented" factory production changes. Don't touch them.
mrnico
Member
Looks like one of these is positive and one is negative. Which one do I need for the 4900? Is it supposed to degauss when you start it cold or after it warms up? Seems to me like the former makes more sense, so you'd want a positive thermistor which has more resistance as it heats up. Thanks.
It degausses at a cold start.....and turns off after warming up.
Edward
Edward
mrnico
Member
That's what I thought, which should indicate a positive thermistor, correct?
Did you determine the proper replacement part?
I checked the MCM site this week, and the stated part #s are no longer available. They have a 3 ohm 144V positive part available, would that work?
I checked the MCM site this week, and the stated part #s are no longer available. They have a 3 ohm 144V positive part available, would that work?
