Search found 64 matches

by hindered
April 2nd, 2017, 6:27 pm
Forum: Monitor Q&A
Topic: Repairing MS8-29FSG
Replies: 88
Views: 4187

Re: Repairing MS8-29FSG

why don't you admit defeat and install a decent ms9-29 chassis-save yourself a lot of hassle Well, my friend, I agree with the point of your message - I already know that I am in over my head on this repair. But, I'm not going to give up on it, for several reasons. A: I don't want this chassis to e...
by hindered
April 1st, 2017, 11:04 pm
Forum: Monitor Q&A
Topic: Repairing MS8-29FSG
Replies: 88
Views: 4187

Re: Repairing MS8-29FSG

I had some time to look at this today. I suspected my VR was shorted again. Removed it from the chassis, confirmed it is shorted via diode test. I powered it up in this state: No F902, No Q901 (VR), no HOT, Pin 2 of flyback isolated. I get 120v AC into the AC pins of the bridge diodes at BD901. I me...
by hindered
March 28th, 2017, 2:04 am
Forum: Monitor Q&A
Topic: Repairing MS8-29FSG
Replies: 88
Views: 4187

Re: Repairing MS8-29FSG

ms8-26 and ms8-29 are completely different chassis I understand this. But I used the ms8-26 schematic as a starting point as a way to visualize the circuit, and compared it to my pcb. The pen drawing on top of the printout matches reality, at least in terms of how the components are connected. Like...
by hindered
March 28th, 2017, 12:36 am
Forum: Monitor Q&A
Topic: Repairing MS8-29FSG
Replies: 88
Views: 4187

Re: Repairing MS8-29FSG

OK, I started from the MS8-26SU schematic and compared it to my PCB: MS8-29 FSG Partial Diagram.JPG Noted differences from the original: 1: C905 and C904 switch order 2: R915 and R911 are parallel for me but in series in the original 3: Many cap/resistor values are different, which I'm capturing els...
by hindered
March 26th, 2017, 3:27 pm
Forum: Monitor Q&A
Topic: Repairing MS8-29FSG
Replies: 88
Views: 4187

Re: Repairing MS8-29FSG

your previous photo did not show that but yes judging from this photo you have connected the bulb to the primary side so your regulation circuit is not working Ok, sorry for the confusion with the previous picture. I'm glad I redrew it for more clarity. I'll focus on understanding the regulation ci...
by hindered
March 26th, 2017, 3:00 pm
Forum: Monitor Q&A
Topic: Repairing MS8-29FSG
Replies: 88
Views: 4187

Re: Repairing MS8-29FSG

that cap is in sync circuit I believe so don't worry about that yet solder the bulb to the primary side of the fuse holder-if you have removed the fuse and then added the bulb further into the circuit then the regulation circuit will not have any load Just to be clear, this is an updated picture ex...
by hindered
March 26th, 2017, 2:29 pm
Forum: Monitor Q&A
Topic: Repairing MS8-29FSG
Replies: 88
Views: 4187

Re: Repairing MS8-29FSG

take the fuse out and attach the bulb there-then meter the voltage The fuse is already out and the bulb is attached there, like in the picture in my previous post. One thing I forgot to mention, there is one cap that is soldered into a resistor position, r556. I'm unsure I have the polarity of that...
by hindered
March 26th, 2017, 5:15 am
Forum: Monitor Q&A
Topic: Repairing MS8-29FSG
Replies: 88
Views: 4187

Re: Repairing MS8-29FSG

to test b+ you need dc volts 200v range,negative to a capacitor ground and positive to pin 2 track of the flyback or the fuse-you can't use the heatshield as ground or the reading will be incorrect Well, in the first configuration as recommended by PrincessPrinPrin, I got 150v dc across the lightbu...
by hindered
March 25th, 2017, 10:01 pm
Forum: Monitor Q&A
Topic: Repairing MS8-29FSG
Replies: 88
Views: 4187

Re: Repairing MS8-29FSG

I think you should do a proper light bulb test. Alright, my friend. You (and grantspain :)) only need to tell me something 6 or 7 times before I decide to listen. :oops: ;) I did both tests, the lightbulb lit up both times. EDIT: I just realized I forgot to measure b+ during the first test, so I we...
by hindered
March 25th, 2017, 5:40 am
Forum: Monitor Q&A
Topic: Repairing MS8-29FSG
Replies: 88
Views: 4187

Re: Repairing MS8-29FSG

is d530 ok? I was finally able to remove this component from circuit and test it. Per the datasheet, there is a diode from pin 1 to 2, and 2 to 3. Although it tests bad in circuit, It tests fine out of circuit. I checked the HV caps for shorts using my meter, everything checked out. Doesn't the fac...
by hindered
March 24th, 2017, 12:13 am
Forum: Monitor Q&A
Topic: Repairing MS8-29FSG
Replies: 88
Views: 4187

Re: Repairing MS8-29FSG

The HOT collector line also goes through a couple of jumpers (yellow) to the damper diode (orange) and the HV caps (pink, blue, red). You can remove the jumpers and repeat the light bulb test or just check if those components are bad. Thank you -- this post set of a chain reaction of understanding ...
by hindered
March 23rd, 2017, 12:44 am
Forum: Monitor Q&A
Topic: Repairing MS8-29FSG
Replies: 88
Views: 4187

Re: Repairing MS8-29FSG

You should have soldered the light bulb to C and E. If the bulb lights up there cannot be a short in either the b+ line going from PSU to flyback (through fuse) or in the line going from flyback to HOT collector (i.e. damper diode and HV poly caps not shorted). And when you put the HOT back in its ...
by hindered
March 23rd, 2017, 12:35 am
Forum: Monitor Q&A
Topic: Repairing MS8-29FSG
Replies: 88
Views: 4187

Re: Repairing MS8-29FSG

I'm working on processing and understanding what you guys said. I currently have pin 2 of the flyback isolated in preparation for testing with the light bulb. I'm 99% sure I'm just going to blow the bulb and short out the voltage regulator and HOT again, though, because I feel the first short is som...
by hindered
March 22nd, 2017, 12:58 pm
Forum: Monitor Q&A
Topic: Repairing MS8-29FSG
Replies: 88
Views: 4187

Re: Repairing MS8-29FSG

The way he reported his test here I'm not sure he used a light bulb at all when doing it. Correct. I have not used a light bulb yet, partly because I'm afraid of shorting out components I don't have replacements for on hand. My test was: F902 and VR replaced. Flyback in place. Use voltmeter between...
by hindered
March 22nd, 2017, 12:11 am
Forum: Monitor Q&A
Topic: Repairing MS8-29FSG
Replies: 88
Views: 4187

Re: Repairing MS8-29FSG

the cap solder link is ok is d530 ok? D530 meters bad in circuit, I get about .400 one way and 2.400 the other way between the same two legs. Assuming I need to test it out of circuit, I'll try to take it out when I get home from the gym. There are huge solder blobs on the parts side though so it l...
by hindered
March 21st, 2017, 2:19 pm
Forum: Monitor Q&A
Topic: Repairing MS8-29FSG
Replies: 88
Views: 4187

Re: Repairing MS8-29FSG

c910 100uf 50v c446 is 33uf 16v bipolar links either side of c446 Thank you for verifying that. Ok, so that means the bipolar cap is standard and we should probably edit the wiki to reflect that. I'll try to find a 50v cap to replace 910 but that wouldn't cause the short... That means the short is ...
by hindered
March 21st, 2017, 3:56 am
Forum: Monitor Q&A
Topic: Repairing MS8-29FSG
Replies: 88
Views: 4187

Re: Repairing MS8-29FSG

No, only the cylindrical electrolytic caps.
by hindered
March 21st, 2017, 3:27 am
Forum: Monitor Q&A
Topic: Repairing MS8-29FSG
Replies: 88
Views: 4187

Re: Repairing MS8-29FSG

ok well the 2 chassis i had here are repaired and on there way back to holland so i will have to see if i have an old chassis in storage to check the caps although i doubt that cap would cause an issue as you can actually remove that horizontal control ic pcb and the chassis will still work Interes...
by hindered
March 20th, 2017, 11:24 pm
Forum: Monitor Q&A
Topic: Repairing MS8-29FSG
Replies: 88
Views: 4187

Re: Repairing MS8-29FSG

i can't see c433 anywhere there,c433 position is right in front of the vertical deflection ic that cap you have pointed on the photo is c446 and in the horizontal size circuit My apologies, I specified the wrong cap in my previous post. I've gone back and fixed the error. The non polarized cap is a...
by hindered
March 20th, 2017, 10:37 pm
Forum: Monitor Q&A
Topic: Repairing MS8-29FSG
Replies: 88
Views: 4187

Re: Repairing MS8-29FSG

grantspain wrote:take a photo of the solder side around c433


With and without C446 installed (I initially desoldered a jumper instead of the cap :oops:)

C446 - 1.JPG
MS8-29 FSG C446 solder side, component installed

C446 - 2.JPG
MS8-29 FSG C446 solder side, component removed

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