Spacecadet28
Member
19k6100 - k6100 monitor help please - low B+ and -25V
Hi all!
Would need a bit a guidance in regards to a K6100 I'm presently working on for my Tempest UR. When I got the game, monitor was dead, no chatter, no deflection, no glow, spot killer on.
This is what I have done so far;
- Replaced all chassis mounted transistors
- Changed the following parts on HV Board (C901-C902-C905-C909-C910-C914-Q901-Q902-Q903-R901-R907-R918- and ZD902 - Flyback)
- Changed the following parts on Neck board C503
- Installed a LV-2K
- Reflowed all header pins on all boards
Powered up and Spot killer on deflection PCB is on.
Checked the chassis mounted transistors and they read as follows;
Q102 32.67 VDC
Q103 -32.6 VDC
Q605 25.19 VDC
Q606 1.17 VDC *****
Q705 25.17 VDC
Q706 1.17 VDC *****
So according to measurement Q706 and Q606 are bad. Like I stated, these are new... So I pulled them and tested them, they test good. I then swapped them with new ones, same. I'm thinking something is pulling them down...
These are the readings on P900
P1 25.17 VDC
P2 25.17 VDC
P5 72.4 VDC
P7 1.18 VDC
P8 1.18 VDC
So I got low B+ at P5 and low -25VDC at P7-P8
On the LV2K board only LD1 is lit. Test points on that side read 25.84VDC at 25V TP and 32.65 VDC at TP 30V. LD2 is not lit and readings on that side are 0.53 VDC at 25V TP and 0.16 at TP 30V.
At this point I'm thinking that there's a problem on the LV section -25V side on the deflection board... I thought that replacing the LV section with the LV2K with take care of that but no. What else should I be looking at?
LMK your thoughts and thanks for your time!
Marty
Hi all!
Would need a bit a guidance in regards to a K6100 I'm presently working on for my Tempest UR. When I got the game, monitor was dead, no chatter, no deflection, no glow, spot killer on.
This is what I have done so far;
- Replaced all chassis mounted transistors
- Changed the following parts on HV Board (C901-C902-C905-C909-C910-C914-Q901-Q902-Q903-R901-R907-R918- and ZD902 - Flyback)
- Changed the following parts on Neck board C503
- Installed a LV-2K
- Reflowed all header pins on all boards
Powered up and Spot killer on deflection PCB is on.
Checked the chassis mounted transistors and they read as follows;
Q102 32.67 VDC
Q103 -32.6 VDC
Q605 25.19 VDC
Q606 1.17 VDC *****
Q705 25.17 VDC
Q706 1.17 VDC *****
So according to measurement Q706 and Q606 are bad. Like I stated, these are new... So I pulled them and tested them, they test good. I then swapped them with new ones, same. I'm thinking something is pulling them down...
These are the readings on P900
P1 25.17 VDC
P2 25.17 VDC
P5 72.4 VDC
P7 1.18 VDC
P8 1.18 VDC
So I got low B+ at P5 and low -25VDC at P7-P8
On the LV2K board only LD1 is lit. Test points on that side read 25.84VDC at 25V TP and 32.65 VDC at TP 30V. LD2 is not lit and readings on that side are 0.53 VDC at 25V TP and 0.16 at TP 30V.
At this point I'm thinking that there's a problem on the LV section -25V side on the deflection board... I thought that replacing the LV section with the LV2K with take care of that but no. What else should I be looking at?
LMK your thoughts and thanks for your time!
Marty
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