Picked up a damaged JBC BD-1BA station... advice? - Page 1
Forum section: electronics / general

author: strobot
author_rank: Contributor
timestamp: October 17, 2013, 11:25:25 pm
content: I picked up a damaged JBC BD-1BA recently and need some advice on tips and handles to get to be able to test it out.It appears to power-on fine and the menu buttons and functions all seem to work. It reports that the handle is missing (which it is). It looks like it was dropped? I thought the shape of the hole in the side was a little unusual, but maybe that's just how that material breaks.

author: strobot
author_rank: Contributor
timestamp: October 18, 2013, 03:29:16 am
content: Ended up buying these:1 (C245-906) C245-906 2245-906 JBC $29.00 $29.00Lead-Free Cartridge* Weight: 0.10 lbs each1 (T245-A) T245-A JBC Tools T245 $63.00 $63.00Standard Handpiece* Weight: 1.00 lbs eachfrom HowardElectronics.That's more than I paid for the station!

author: M. András
author_rank: Super Contributor
timestamp: October 18, 2013, 08:44:58 am
content: thats a serious damage

author: strobot
author_rank: Contributor
timestamp: October 18, 2013, 03:35:22 pm
content: Quote from: M. András on October 18, 2013, 08:44:58 amHopefully its only cosmetic

author: fenclu
author_rank: Regular Contributor
timestamp: October 18, 2013, 04:12:29 pm
content: It looks like it's been burnt out. Almost as if it was standing next to a torch or something...

author: Gromitt
author_rank: Regular Contributor
timestamp: October 18, 2013, 04:22:22 pm
content: Quote from: fenclu on October 18, 2013, 04:12:29 pmNo, it has been knocked out by the transformer inside the case./stefan

author: codeboy2k
author_rank: Super Contributor
timestamp: October 19, 2013, 09:52:12 am
content: Yep... I would agree... likely it fell off the table, and the transformer inside punched out the sidewall as it flexed.

author: nctnico
author_rank: Super Contributor
timestamp: October 19, 2013, 10:35:40 am
content: Glue a piece of plexiglass over it after putting some LEDs inside with your favourite color

author: SeanB
author_rank: Super Contributor
timestamp: October 19, 2013, 11:39:18 am
content: To fix it place duct tape inside to cover the hole then use 2 part epoxy to fill in the now flat backed place. When cured remove the tape and finish off the outside with a bit of sandpaper or a file and paint it. Otherwise get a small tin of car body putty and hardener and do the same, though that will be a little weaker. I have done this a lot of times to plastic cases and bakelite that has cracked.

author: Hydrawerk
author_rank: Super Contributor
timestamp: October 19, 2013, 01:38:29 pm
content: This cannot happen to my old ERS50, that is made of solid steel. Manufactured in 1990. On the other hand, the soldering tip is not perfect.

author: strobot
author_rank: Contributor
timestamp: October 19, 2013, 01:55:59 pm
content: Thanks SeanB, I'm going to give that a try.I disassembled it and the internals look fine.

author: SeanB
author_rank: Super Contributor
timestamp: October 19, 2013, 01:59:48 pm
content: That 470uD 25V SM cap there on the top has broken loose from the solder pad though, likely from impact. I would reflow all the other big caps as well just in case.

author: strobot
author_rank: Contributor
timestamp: October 19, 2013, 02:34:45 pm
content: I just took a closer look, and the solder on the pads looks pretty good. I'll give them a touch just in case.

author: strobot
author_rank: Contributor
timestamp: October 21, 2013, 11:10:04 pm
content: OK, I've completed the repair... somewhat. It was a shitshow.I used West System resin and hardener for the first go. I taped up the inside of the box with duct tape and let the epoxy cure overnight. The fact that the hole curves around the side of the enclosure made it hard to get a good internal seal due to internal small radii curves inside the enclosure. I also had to curve a piece of tape externally to prevent epoxy from simply draining down the low point of the curve-hole onto the faceplate of the station. This external taping proved marginally effective, as epoxy still leaked and cured onto the metal plate. I had to scrape off the hardened epoxy and ended up sanding the face to get rid of the resultant scratches.The incomplete internal seal caused epoxy to leak through and cure on various locations inside the enclosure, including the tempered glass LCD shield. I tried chipping the epoxy off the glass and ended up cracking the glass. In a rage, I decided that I'd rather have no glass than cracked glass and busted the rest out. Since so much leaked out of my pool of epoxy, there ended up being a hole in the epoxy patch and the patch was not level with the outer surface of the enclosure.Since the surface of the enclosure opposite the hole didn't have a perfectly matching parallel surface that I could have rested the enclosure on, I had to jerry-rig bits of paper towel between the table and the enclosure to make sure the epoxy didn't cure at a non-parallel angle to the enclosure face. This ended up not being perfect anyways and the epoxy cure wasn't exactly parallel to the enclosure face.The second time around, I used epoxy + low density filler (West System), which made the epoxy much more viscous and easy to manage. That is the reason why there is a region of clear epoxy (at the curved section of the hole) and chocolate milk epoxy (epoxy + filler). Another one of the problems with using tape on the inside is that there is this thing called gravity that causes the tape to sag from the weight of the epoxy, so the patch sags somewhat towards the inside of the enclosure.In retrospect, I approached this the complete wrong way. It would have been much better to first tape theoutsideof the enclosure and rest the hole-face on a known level surface. Then, I could have poured epoxy from the inside of the enclosure and have a nice, flat, parallel patch. There would still be a small gap left over at the uppermost section of the curved part of the hole that could have been patched in a second curing operation with tape on the inside.