UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > General Vintage Technology > Components and Circuits

Notices

Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets.

Closed Thread
 
Thread Tools
Old 7th Aug 2017, 3:41 pm   #21
mhennessy
Dekatron
 
Join Date: Jul 2007
Location: Evesham, Worcestershire, UK.
Posts: 4,241
Default Re: Fuse for Fluke 8062A

Ah! I didn't realise that Farnell's price was that low - I didn't follow the links in post #2 because when I came to this thread this morning, higher prices than that were being discussed so I assumed that neither of the links had got us any further forward. A fiver isn't a bad price for piece of mind
mhennessy is offline  
Old 7th Aug 2017, 4:04 pm   #22
Guest
Guest
 
Posts: n/a
Default Re: Fuse for Fluke 8062A

At a fiver I change my mind.
 
Old 11th Aug 2017, 3:04 pm   #23
WaveyDipole
Nonode
 
WaveyDipole's Avatar
 
Join Date: Mar 2013
Location: Leicester, UK
Posts: 2,505
Default Re: Fuse for Fluke 8062A

The new HRC fuses arrived yesterday and I fitted one today. I was able to complete all the tests including the resistance and diode test, ratio self test and switch decoding test. Voltages on all the test points that I could actually find (TP 2, 7, 8) were within specificaton and a trigger pulse was present on TP6 as well as a 40kHz signal on TP9. So far, so good.

Unfortunately while I was replacing the cover, disaster struck! On replacing one of the two screws behind the display, I heard a slight crack... On turning on the meter, the display showed L L L L instead of 0 0 0 0. Having removed the lid again, I found that on the back of the LCD module there is a plastic bar that retains the PCB and puts pressure against the LCD. The lug on one side had cracked and broken off. I am not terribly hopeful, but I am attempting to repair this with epoxy adhesive and will know tomorrow whether the resulting repair is strong enough and whether there still is sufficient pressure to enable the LCD to show the digits correctly. Has anyone had this happen? I don't quite know how or why this happened but when I fist removed the lid, one of the three plastic screw mount points in the lid was cracked already and a piece fell off. I have already repaired it with the same epoxy adhesive. I also noticed that both screw mount points on the LCD section were cracked as well. I am wondering whether the plastic is getting so brittle that it is prone to cracking at the slightest bit of stress? Evidently screwing in that last screw somehow caused sufficient flex and stress to cause that part to break even though it is not directly connected with the case or the mount point. The infuriating thing is that I was actually trying to be careful and not put too much pressure on the case!

With the LCD removed, I can see that all of the caps look clean and the meter otherwise works fine so I'm trying to decide whether to leave well alone or having read about leaking cap issues, whether to re-cap? It will, of course, depend on how well the repair goes. If it fails there will probably be no point and I might end up having to sell the parts to recover some of the cost.

I appreciate this is going OT a bit as the OP specifically discussed the fuse, but it still relates to this meter so I am happy for mods to change the thread title.
Attached Thumbnails
Click image for larger version

Name:	cracked-LCD-lug.jpg
Views:	72
Size:	53.7 KB
ID:	147679   Click image for larger version

Name:	cracked-LCD-points.jpg
Views:	72
Size:	70.7 KB
ID:	147680   Click image for larger version

Name:	cracked-cover-mount-point.jpg
Views:	70
Size:	24.8 KB
ID:	147681  

Last edited by WaveyDipole; 11th Aug 2017 at 3:12 pm.
WaveyDipole is offline  
Old 12th Aug 2017, 10:12 am   #24
WaveyDipole
Nonode
 
WaveyDipole's Avatar
 
Join Date: Mar 2013
Location: Leicester, UK
Posts: 2,505
Default Re: Fuse for Fluke 8062A

Well the good news is that the repair with the epoxy adhesive was successful. I released the clamp this morning and the joint seems to be holding. I reattached the display to the main board using minimal tension on he mounting screws so as to prevent further damage to the already cracked mount points and have re-assembled everything. The display shows all segments correctly and the meter functions as expected. While re-assembling I realised that the break occurred on the opposite side of the display to the screw I was working on at the time so I am puzzled as to how this might have actually happened in the first place. At least the money I spent on the spare HRC fuse was not wasted after all!

Last edited by WaveyDipole; 12th Aug 2017 at 10:23 am.
WaveyDipole is offline  
Old 12th Aug 2017, 11:37 am   #25
MrBungle
Dekatron
 
MrBungle's Avatar
 
Join Date: Jun 2016
Location: London, UK.
Posts: 3,687
Default Re: Fuse for Fluke 8062A

Looks good. The plastic does go quite brittle.

Yes definitely recap it! I've had one that the electrolyte leaked out and ate the ribbon cable in it. Pictures of the carnage below

Click image for larger version

Name:	IMG_20170217_220323405.jpg
Views:	91
Size:	33.9 KB
ID:	147726

Click image for larger version

Name:	IMG_20170216_231108721.jpg
Views:	80
Size:	33.2 KB
ID:	147727

Before I forget to add, the only end game on the 8060 series is the LCD display being damaged. The 8010/8020 series you can make a new display for about £5 and some fiddly manual labour. I've done this twice now. Never again!

Here's a before/after:

Click image for larger version

Name:	IMG_20170216_222501.jpg
Views:	107
Size:	108.8 KB
ID:	147728

Click image for larger version

Name:	IMG_20170224_171506.jpg
Views:	109
Size:	41.5 KB
ID:	147729

There's half a roll of kynar in the fixed one!

Last edited by MrBungle; 12th Aug 2017 at 11:45 am.
MrBungle is offline  
Old 12th Aug 2017, 1:22 pm   #26
WaveyDipole
Nonode
 
WaveyDipole's Avatar
 
Join Date: Mar 2013
Location: Leicester, UK
Posts: 2,505
Default Re: Fuse for Fluke 8062A

The damage to that ribbon looks nasty and no doubt unrepairable. Regarding the display, is that the so called LCD bleed problem? Although its actually readable, I have never seen one looking like that before!
WaveyDipole is offline  
Old 12th Aug 2017, 2:10 pm   #27
mhennessy
Dekatron
 
Join Date: Jul 2007
Location: Evesham, Worcestershire, UK.
Posts: 4,241
Default Re: Fuse for Fluke 8062A

I read recently that the display bleed problem only happens with the 8010/8020 displays because they were made in the USA "for political reasons". The 8060A screens were made by Sharp.

Now if this sounds a bit anecdotal, it comes from Dave Taylor, who designed the 8060A. The source is here: https://www.eevblog.com/forum/testge...28/#msg1277328

For anyone interested in these old meters - and the 8060A/8062A is a real treasure - the whole thread is worth skimming.

NB: I haven't listened to the whole podcast, but here it is: https://theamphour.com/180-an-interv...d-meter-maker/
mhennessy is offline  
Old 12th Aug 2017, 3:00 pm   #28
mhennessy
Dekatron
 
Join Date: Jul 2007
Location: Evesham, Worcestershire, UK.
Posts: 4,241
Default Re: Fuse for Fluke 8062A

Quote:
Originally Posted by mhennessy View Post
NB: I haven't listened to the whole podcast, but here it is: https://theamphour.com/180-an-interv...d-meter-maker/
42 minutes in for the comments about the displays
mhennessy is offline  
Old 12th Aug 2017, 6:17 pm   #29
MrBungle
Dekatron
 
MrBungle's Avatar
 
Join Date: Jun 2016
Location: London, UK.
Posts: 3,687
Default Re: Fuse for Fluke 8062A

Wouldn't surprise me. However I've seen the same thing on an 8060A before.

Quote:
Originally Posted by WaveyDipole View Post
The damage to that ribbon looks nasty and no doubt unrepairable. Regarding the display, is that the so called LCD bleed problem? Although its actually readable, I have never seen one looking like that before!
The cable was repairable. Required IPA and scrubbing with a fibreglass pencil. It had only oxidised the surface fortunately. The real concern is contact resistance as some of the lines are high impedance but you can actually turn the cable around and get away with it sometimes.

The display is one of the failure mode. It usually creeps in from the edges to total blackness but this was a weird one.

The big problem with this meter was it wouldn't auto zero. Took hours of scrubbing with IPA and cleaning switches to get it back. Works perfectly now though
MrBungle is offline  
Old 12th Aug 2017, 7:55 pm   #30
mhennessy
Dekatron
 
Join Date: Jul 2007
Location: Evesham, Worcestershire, UK.
Posts: 4,241
Default Re: Fuse for Fluke 8062A

Quote:
Originally Posted by MrBungle View Post
Wouldn't surprise me. However I've seen the same thing on an 8060A before.
And occasionally you can find an original 87 with similar problems, for example. And no-doubt others, from any manufacturer if you look hard enough. However, most 8010/20 displays will be toast by now, whereas most 8060 displays will still be just fine - there's no doubt the Sharp displays were a big step forward.

Dave Taylor is the best source we've got at this point in time. I'm about half way through the podcast - it's an excellent listen
mhennessy is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 12:31 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.