Eurosealer Does Not Heat - Page 1
Forum section: electronics / repair

author: Boris_yo
author_rank: Frequent Contributor
timestamp: December 28, 2020, 08:58:16 am
content: Hello,I bought this sealer around 7 years ago or so and never turned it on. It was collecting dust in kitchen's cabinet until today. I wanted to use it to seal some bags but noticed that it's heating pad does not heat. Tried putting different AA batteries in different directions too but to no avail. I have disassembled sealer but have no idea what is wrong.Any ideas?

author: Ian.M
author_rank: Super Contributor
timestamp: December 28, 2020, 10:09:42 am
content: Well, that's a fairly useless photo. You haven't shown us the heating element connections. I assume the element is the T-shaped block on the far left with the wire in it under the (probably) PTFE impregnated glasscloth tape. Turn the T-block over and take a good closeup!Judging by the spring between the contacts at the left end of the battery compartment, it requires the T-block to be pressed down to make contact. If the terminals are dirty or oxidized, it may not make reliable contact.Don't waste your time with 'Heavy Duty' batteries as they are no more than Zinc Chloride cells with more Manganese Dioxide depolarizer, so their internal resistance is too high fresh out the pack, - most cant even deliver an amp at 0.75V for six minutes from fresh - so your typical 2x AA hot element gadget *REQUIRES* reasonably fresh alkaline AA cells to work as specified. Once they cease to provide sufficient heat they've still probably got half their life left if you give them a day or so to recover and use them in a low drain application, but their seals may well have been stressed by internal gas pressure and high terminal temperature, so don't trust them not to leak in anything valuable.

author: Haenk
author_rank: Super Contributor
timestamp: December 28, 2020, 10:13:53 am
content: Measure the resistance of the "heating block" (there should be some very low ohmish resistance - and use good alkaline batteries. Maybe pull up the contact tabs a bit.

author: Boris_yo
author_rank: Frequent Contributor
timestamp: December 28, 2020, 10:32:16 am
content: @lan.MI made top and bottom photos of heating element.

author: Ian.M
author_rank: Super Contributor
timestamp: December 28, 2020, 10:56:36 am
content: OK, it works as thought it did.I assume you've got a DMM. What resistance do you measure between the rivets? If its over a few ohms, check between the element wire and the rivet.Its a pity you peeled the covering tape - its likely to be rather difficult to get it to stick back on and there's no easy source for replacement tape with fresh adhesive on less than 10m reels!

author: Boris_yo
author_rank: Frequent Contributor
timestamp: December 29, 2020, 07:03:22 am
content: Quote from: Ian.M on December 28, 2020, 10:56:36 amAre you talking about measuring resistance of that T-block / heating element? If you are, then I measured resistance between 2 rivets as multimeter was set to 200 ohm criteria. The reading showed 01.7-02.0 and when I measured between rivet and wire it showed 01.6-0.20

author: Ian.M
author_rank: Super Contributor
timestamp: December 29, 2020, 09:05:25 am
content: Hmm. It seems likely that your DMM doesn't have an auto zero mode for resistance ranges (most budget ones don't) and most those resistance values are due to contact resistance from the DMM probes. Please find a piece of solid bare (or tinned) copper wire of roughly the same diameter, and check what your meter reads on the same 200R range when you use the wire to short the probes, with the probes close together, not touching.However its obvious that the resistance of the heating element is so low that it must be intended to draw several amps, so as I and Haenk have already said,good quality, fresh Alkaline AA cells are essential.You can also check that the heating element competes the circuit when pressed down by (partial) reassembly and measuring resistance between the battery terminals it connects to (without the batteries in), while you push it down firmly against the spring pressure. It should go from open circuit to slightly over the resistances you have already measured when it makes contact. If it fails to make contact try bending up the contact tabs *slightly* as Haenk has already suggested, but its *ESSENTIAL* that it breaks contact with a reasonable gap when pressure is released so don't bend them up too far.

author: Boris_yo
author_rank: Frequent Contributor
timestamp: December 30, 2020, 09:50:53 am
content: @Ian.MI used solder wire and tied it to one probe's end and another probe's end. Reading was jumping back and forth 1.3 to 1.9 then I removed solder wire from probes and measured between one battery contact tab and another battery contact tab while firmly pressing down heating element. The reading was jumping back and forth between 2.9 and 10

author: Ian.M
author_rank: Super Contributor
timestamp: December 30, 2020, 11:11:02 am
content: Shorting the probes like that should have given a resistance close to zero, certainly under one ohm. It seems like you are getting lots of bad connections. Try cleaning your probes with high purity alcohol (isopropanol, ethanol or methanol doesn't matter which) on a wadded up paper towel, twisting the probe while pinching it firmly in a fold of the paper towel. For the rivets on the heating element and the battery contacts, try wiping them with alcohol, and if that doesn't decrease the contact resistance significantly and make it more stable, lightly abrade them with either a fibreglass pencil brush (preferred), 800 grit or finer wet&dry paper, or a typist's erasor (abrasive rubber), then re-clean with alcohol.

author: Boris_yo
author_rank: Frequent Contributor
timestamp: December 30, 2020, 12:04:52 pm
content: @lan.MI don't have fibreglass pencil brush and abrasive rubber but I can buy sandpaper. Will nail file be good if I find it at home?

author: Ian.M
author_rank: Super Contributor
timestamp: December 30, 2020, 01:00:24 pm
content: No, a nail file would be far to coarse and you'd need the abrasive to be flexible so it conforms to the surface. 800 grit is a *VERY* fine grit sandpaper, too fine for regular use with wood or 'one pot' paint, used mostly for car body paintwork to flat down hard 'two pot' primer before topcoating. Its so fine you could wipe your ass with it without injuring yourself!

author: DTJ
author_rank: Super Contributor
timestamp: December 30, 2020, 01:24:05 pm
content: Quote from: Ian.M on December 30, 2020, 01:00:24 pmWell explained!

author: Boris_yo
author_rank: Frequent Contributor
timestamp: February 04, 2021, 11:02:04 am
content: @Ian.MI used 800 grit sandpaper on 2 heating element's connectors and on battery contacts. Nothing made difference. Don't know what is wrong.