@@The_Studioworkshop can't fire up the iiyama yet as I left it in the car and when I came back to it there was loads of condensation on front of the screen. I'm now worried there's loads inside too so I'm wait for it to dry out!
@@845H1R sounds like a few days in a warm room might be worth while. Condensation is a big killer. Moisture in transformers etc. once it’s at room temp I’m sure it’ll be safe to power on with no issues. It’s so cold these days, I’m wearing 3 jumpers and I’m still feeling a chill!
LOPT is somewhat infamous for going on these as I understand it. I had mine replaced a couple of years ago. Unfortunately the replacement seems to bloom/breathe noticeably more than the original. Also now the audio board is playing up and the vertical size periodically jitters. I should of left it in the loft...
Well yes and no. Awhile ago, I condemned a lot of these failures to poor solder joints, as described in my video and other units I have worked on and posted on the channel. The poor joints generate heat in the transformer, hot spots, from there, they short. 15khz is quite a large pulse, so bad connections generate carbon tracking and all sorts of nasties. Hence why people are reporting replacements are failing. They tend to not bother reflowing the PCB! As for blooming, have you ensured the main HT preset is setup correctly? The small potentiometer on the PSU.
@@The_Studioworkshop I didn't do the repair myself, a local chap in S.E London did. He also replaced some caps on the PSU and the neckboard and installed a new power switch. So you're saying it's likely poor joints that take out the LOPT's and not the LOPT itself? Regarding the blooming, there's a very good video on TheRetroChannel where he compares a replacement LOPT with a NOS original in the same monitor and it does appear from his tests that this is something inherent with the replacements. It's here if you're interested. th-cam.com/video/7z6T64Elm-s/w-d-xo.html
@@Grim177it’s a mixed bag. Transformers can fail by poor insulation inside, however a lot of these tend to suffer poor solderjoints, and cause the transformer to get hot, the insulating material fails, and windings short. I’ve done other videos on these monitors going over similar issues! Sometimes the diode can fail, or even the whole focus and g2 divider. In the past I’ve added an external diode insulated in a silicone tube for safety. No point replacing the transformer if you can repair it easily, you know? Saves money and time! I’ll take a look now. Blooming can be common with low EHT. I’ve worked on a couple monitors with replacements, but I’ve not noticed this. You can measure the EHT, if it drops when the brightness is turned up, this would cause the blooming affect. It’s worth saying that the replacements fail too, as the same issues with the poor joints happen again. Why I always hammer home the touch up solder joints point. I didn’t know there was another chap in SE London! I thought I was the only one! I know there’s an old boy down the road from me. Osborne services. Seems very competent but didn’t think he was taking business. Old school shop.
@@Grim177additionally, if EHT is low, you can change the horizontal tuning caps. You may need to experiment with these values. The whole thing is a fixed tuned circuit. Sometimes the drop in replacements aren’t always the same. Inductances are different. You can change the values of the tuning caps, to give better results, as a guess. Otherwise low main B+ is w thought too.
I am in North Cheshire and I am trying to find someone that can repair a Commodore 1701 Monitor if you or your followers can do it? The tube is ok, but the boards are knackered due to someone else having a go at replacing the caps (Not me :D ).
Nice one Ed!
Thanks Bashir! Hope all is well.
@@The_Studioworkshop can't fire up the iiyama yet as I left it in the car and when I came back to it there was loads of condensation on front of the screen. I'm now worried there's loads inside too so I'm wait for it to dry out!
@@845H1R sounds like a few days in a warm room might be worth while. Condensation is a big killer. Moisture in transformers etc. once it’s at room temp I’m sure it’ll be safe to power on with no issues. It’s so cold these days, I’m wearing 3 jumpers and I’m still feeling a chill!
LOPT is somewhat infamous for going on these as I understand it. I had mine replaced a couple of years ago. Unfortunately the replacement seems to bloom/breathe noticeably more than the original. Also now the audio board is playing up and the vertical size periodically jitters. I should of left it in the loft...
Well yes and no. Awhile ago, I condemned a lot of these failures to poor solder joints, as described in my video and other units I have worked on and posted on the channel. The poor joints generate heat in the transformer, hot spots, from there, they short. 15khz is quite a large pulse, so bad connections generate carbon tracking and all sorts of nasties. Hence why people are reporting replacements are failing. They tend to not bother reflowing the PCB!
As for blooming, have you ensured the main HT preset is setup correctly? The small potentiometer on the PSU.
@@The_Studioworkshop I didn't do the repair myself, a local chap in S.E London did. He also replaced some caps on the PSU and the neckboard and installed a new power switch. So you're saying it's likely poor joints that take out the LOPT's and not the LOPT itself? Regarding the blooming, there's a very good video on TheRetroChannel where he compares a replacement LOPT with a NOS original in the same monitor and it does appear from his tests that this is something inherent with the replacements. It's here if you're interested. th-cam.com/video/7z6T64Elm-s/w-d-xo.html
@@Grim177it’s a mixed bag. Transformers can fail by poor insulation inside, however a lot of these tend to suffer poor solderjoints, and cause the transformer to get hot, the insulating material fails, and windings short. I’ve done other videos on these monitors going over similar issues! Sometimes the diode can fail, or even the whole focus and g2 divider. In the past I’ve added an external diode insulated in a silicone tube for safety. No point replacing the transformer if you can repair it easily, you know? Saves money and time!
I’ll take a look now. Blooming can be common with low EHT. I’ve worked on a couple monitors with replacements, but I’ve not noticed this. You can measure the EHT, if it drops when the brightness is turned up, this would cause the blooming affect. It’s worth saying that the replacements fail too, as the same issues with the poor joints happen again. Why I always hammer home the touch up solder joints point.
I didn’t know there was another chap in SE London! I thought I was the only one! I know there’s an old boy down the road from me. Osborne services. Seems very competent but didn’t think he was taking business. Old school shop.
@@Grim177additionally, if EHT is low, you can change the horizontal tuning caps. You may need to experiment with these values. The whole thing is a fixed tuned circuit. Sometimes the drop in replacements aren’t always the same. Inductances are different. You can change the values of the tuning caps, to give better results, as a guess.
Otherwise low main B+ is w thought too.
One question. Mine gets pulsing very slightly on vertical axis. What is the cause of this? thnx
Not sure how you mean. Take a video, tag me in it!
I am in North Cheshire and I am trying to find someone that can repair a Commodore 1701 Monitor if you or your followers can do it? The tube is ok, but the boards are knackered due to someone else having a go at replacing the caps (Not me :D ).
Absolutely! What’s wrong with it?
Please get in touch em536716@gmail.com
Any updates on this?