15th Jan 2019, 12:29 am | #141 |
Octode
Join Date: Jun 2018
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Re: CRT is brighter to one side [Hitachi CTP213]
I'll have a look tomorrow when I get home. I think there was some replacements done in the past, as the soldering looks slightly different to the usual precision soldering.
Thank you all for your help! |
15th Jan 2019, 11:34 pm | #142 |
Octode
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Re: CRT is brighter to one side [Hitachi CTP213]
I've just had a look, and I think I've found a crack. I'm not 100% sure if it is a crack, I did think it could be some dirt but I got some IPA and a cotton bud, and cleaned the area and it didn't make a difference.
The crack is next to a capacitor I replaced, so could be because of this. How would I fix it? Do I need to get another capacitor and keep the leg and fold it over, or is there another way? Thanks |
15th Jan 2019, 11:38 pm | #143 |
Dekatron
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Re: CRT is brighter to one side [Hitachi CTP213]
See Refugees post 137 on how to repair the cracked joint.
No need for a new cap at this stage, just resolder.
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15th Jan 2019, 11:43 pm | #144 |
Octode
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Re: CRT is brighter to one side [Hitachi CTP213]
Sorry if this is a simple thing, but should I resolder the tracks, or the feed outs to the track, as I cut the remaining metal off the feed outs back when I replaced the caps.
Thanks for the fast reply! |
15th Jan 2019, 11:53 pm | #145 |
Rest in Peace
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Re: CRT is brighter to one side [Hitachi CTP213]
Scrape away the solder-mask for a few mm either side of the crack. Either bridge with a nice smooth blob of solder, or if the crack has opened even slightly, preventing the solder flowing across, solder a little piece of tinned copper wire like a cut-off component lead across it. There's no need to disturb the capacitor
BTW, are you using 60/40 leaded solder? You should be, as lead-free solder will not work well on old equipment that was made with leaded, and your joints will be poor. |
16th Jan 2019, 12:01 am | #146 |
Dekatron
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Re: CRT is brighter to one side [Hitachi CTP213]
I don't usually link to this sort of thing - too much clickbait and half-baked 'advice' from people who don' t really know what they're on about - but this shows quite well how to prepare the board trace prior to remaking the joint.
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16th Jan 2019, 12:33 am | #147 |
Octode
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Re: CRT is brighter to one side [Hitachi CTP213]
Hi, thanks for the replies.
Ben - Thanks for the link, I’ll have a read of that after writing this. Lucien Nunes - Thanks for your help - It’s really appreciated. About the solder, im not sure. I have a kit that was given to me so i’m not sure which it is. I use the solder which is given in the kit. I can have a look tomorrow to see if there is any information in the kit, but i don’t think there is. Thanks |
18th Jan 2019, 11:01 pm | #148 |
Octode
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Re: CRT is brighter to one side [Hitachi CTP213]
Update:
PCB didn't have a crack, it was just some grime which looked like a crack. I guess my next shot is to have a look at the resistor and diodes which were mentioned before my 1100 Man. Thanks for your help |
21st Jan 2019, 8:52 pm | #149 | |
Octode
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Re: CRT is brighter to one side [Hitachi CTP213]
Hi,
I'm just about to test the components 1100 Man said to test, diodes, resistor and capacitors. I was unsure of which to test for a diode as it's said CR703 has gone short circuit, but is then said to test CR103 Quote:
Thanks |
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21st Jan 2019, 9:47 pm | #150 |
Octode
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Re: CRT is brighter to one side [Hitachi CTP213]
"Should I test CR703, or CR103."
That would appear to be a typographical error on my part- sorry about that! CR703 is the suspected diode. Have you now got a multimeter ? Cheers Nick |
21st Jan 2019, 9:51 pm | #151 |
Octode
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Re: CRT is brighter to one side [Hitachi CTP213]
I did think it was CR703, just wanted to make sure.
I do, and I have also tested R727, which is allowing no current through at all. - Replacement being ordered soon I will now test CR703, and come back with my results. Thank you for your help! |
21st Jan 2019, 10:41 pm | #152 |
Octode
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Re: CRT is brighter to one side [Hitachi CTP213]
I don't know if I'm doing something wrong, but I cannot get a result from CR703, either.
I'm not too bothered about R727 not giving a result, as either way I'd like to replace it, due to the burn on it. Any help would be appreciated as to how to get a reading/why i'm not. Thanks |
21st Jan 2019, 11:01 pm | #153 |
Octode
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Re: CRT is brighter to one side [Hitachi CTP213]
What setting do you you have your multimeter on and how are you actually testing the diode?
How did you test the resistor R727? Nick Last edited by 1100 man; 21st Jan 2019 at 11:02 pm. Reason: extra text added |
21st Jan 2019, 11:12 pm | #154 |
Octode
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Re: CRT is brighter to one side [Hitachi CTP213]
My multimeter is on the diode setting with the diode symbol, and I have put red on the left side, black on the right, and visa versa with no luck either way.
Edit: This is on top of the PCB, where I can see the diode itself I did the same with the resistor (switching wires over) but cannot remember which setting, I went through various settings. Thanks |
24th Jan 2019, 12:05 am | #155 |
Octode
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Re: CRT is brighter to one side [Hitachi CTP213]
I think I will replace diode CR703 just to be on the safe side as I can't get a reading on the multimeter.
What type of diode would this be as it has no information in the service manual Thanks |
28th Jan 2019, 6:14 pm | #156 | |
Octode
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Re: CRT is brighter to one side [Hitachi CTP213]
Hi
I thought I would link this thread to the now closed "What Diode?" thread. "What diode?" https://www.vintage-radio.net/forum/...d.php?t=153497 Quote:
The resistor is a 1.8kohm metal oxide resistor. I have ordered a replacement, valued at 2watts which I was told should be okay. How do I fix the shading? I was told replacing two capacitors would sort this, which I have changed, and that's when I had no picture. Thanks Ah right so it is the A1/screen diode, the confusion earlier was down to me, as I was under the impression it was the RGB 200v supply that was in trouble, my mistake. Okay, do you know which A1 it would be from the list (See attached) as there are multiple. Thanks Thank you all for your help! It's really appreciated. |
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28th Jan 2019, 6:31 pm | #157 |
Dekatron
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Re: CRT is brighter to one side [Hitachi CTP213]
There is not enough context in that image for me to know what A1 means, I suspect there is a physical PCB layout diagram associated with it, with X-Y co-ordinates.
What we mean by A1 however, is the CRT first anode. I don't blame you for misunderstanding the jargon which must be new to you.
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-- Graham. G3ZVT Last edited by Graham G3ZVT; 28th Jan 2019 at 6:45 pm. |
28th Jan 2019, 6:54 pm | #158 |
Octode
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Re: CRT is brighter to one side [Hitachi CTP213]
Oh my mistake, I just get a little confused at times.
I don't know how to read schematics very well, I just find them useful for finding parts on the board more than anything. My guess that diode could be CR092 or CR093? i could be very wrong. Thanks. |
28th Jan 2019, 6:56 pm | #159 |
Octode
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Re: CRT is brighter to one side [Hitachi CTP213]
Maybe these photos could help?
Edit: 2nd image is location D7 |
28th Jan 2019, 7:07 pm | #160 | |
Dekatron
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Re: CRT is brighter to one side [Hitachi CTP213]
I deleted a post in error....here it is again:
Quote:
I've already pointed out what diode is what so far as CR703 (the subject of the diode thread) is concerned...…(location square D7 on the schematic) EDIT: Post crossed. Lawrence. |
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