Sounds like a thermal problem. You could try to open the device and see if there is a lot of dust. Vacuuming carefully, not touching any electronics, might help. Maybe that one of the components gets very hot to the touch… Or simply sell the box for parts and get on with camera scanning.
Ok, I will try to clean the dust.
Thank you again.
[Top] 100% crop. Hasselblad Flextight X1 @ 6,300 spi.
[Bottom] 100% crop. Sony a7R IV, Sony FE 90 mm F2.8 Macro G OSS.
This is my first test, and a quick test.
For at least 35mm slide film, I am amazed that digital camera rival or outperform my Flextight X1 scanner.
I am very satisfied. 
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Wow imprssive!
Espacially as you seem to be a skilled Flextight User, im pretty happy to see what its possible to archive with Cam Scan + NLP.
Curios abou more examples 
That example image is a very old 35mm slide film. I didn’t shoot much with 35mm film.
Anyway, I tested my 4x5 slide films.
When I took two split shots with the a7R IV and stitched them into one, the a7R IV began to outperform the Flextight X1 scanner.
4x5 films require two shots, but I am very happy with the results. 
The a7R IV will now take the place of the 15-year-old Flextight X1 scanner.
My setup is not yet fully ready. When I’m ready, I’ll test again and upload a test image. 
p.s. The 16-shot pixel shift function didn’t really help.
p.s.2. Lightroom’s Enhance Details feature helped a little.
Oh interesting to hear, the 16 Shot Pixel shift function does not really help.
Was always curios if this could be a quality boost.
Im staying curios - following the Thread by notification.
Happy Scanning
In my quick test, the 16-shot pixel shift function did not produce meaningful results. I was also surprised and disappointed. 
Today I got a Besseler 45V-XL and Durst M805 BW enlargers for free from a friend.
These enlargers were rarely used and left in the warehouse.
Anyway, I’m going to attach the camera to one of these enlargers.
Then, I will test it seriously.
I purchased the Epson Fluid Mount Accessory for camera scanning, and as a trial, I also purchased the 8x10" Tru Vue Museum Picture Frame Glass.
I put a 4x5 slide film on the Kaiser lightbox and covered it with TRU VUE museum glass.
And both 35mm and 4x5 slide film were captured perfectly. It is perfectly flat.
It is a bonus that all the edges of the film come out.
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Cant imagine the time you spend on cleaning up scans with so many surfaces and LF. But yes, keeping LF flat without glass is impossible.
Did you experience any Newton rings?
R.
I use TRU VUE museum glass to scan 4x5 films.
Newton rings may or may not appear on the slide film.
Black and white film is fine.
These days, I am testing ANR glass.
AN glass will help — Every other galss will give you rings sometimes … Normal glass works only when the emulsion side is very matte. But most modern color negatives have both sides very glossy so it is harder …
The problem with 35mm BW negative scanning with my Imacon 848 has been that the abrasions and also some embedded dust show in the scan and this requires a lot of spotting in Photoshop, even though these abrasions are not visible when I make a large print. The scanning process sees them. How much of these abrasions does the Sony a7R IV capture? I print my digitized negatives to 24x36 inches and sometimes have labs do larger prints, so I need a very clean scan - not dust or scratches showing. (These are not scratches on the negative. They are just “rub marks” from moving the negs around over the years and to be clear, they are not visible when I make a print with my Leitz enlarger and APO schneider enlarging lens. I would appreciate a respons becasue it is this question which will determine whether I explore camera scanning rather than Imacon.
If the film has abrasions and dust, the camera scan will capture the contaminants, as will the Imacon.
But if the film is clean, the camera scan will produce a clean image as well as Imacon.
I use film cleaner to remove contaminants as needed.
You might consider starting a separate thread as I’d say your particular issues with Imacon scans are quite unusual. Then you could provide examples of quite what you mean, perhaps a 1:1 crop of the area from the Imacon scan that show these ‘abrasions’ and maybe a close-up of the same area from one of your large prints. The Imacons use a fluorescent tube and that acts more or less like a point source, ‘more or less’ because the tubes vary according to model and the Imacon 949 and Hasselblad X5 added a small amount of diffusion. I’ve yet to see a side by side comparison of how effective that was.
You don’t say which Leitz enlarger that you are using, most have either a single of double condenser but the V35 has a diffuser light source. It is the light source that is key here I think. It has been demonstrated that when ‘camera scanning’ in order to extract the most resolution from (particularly) a B&W negative you need to have a collimated light source, and of course in order to do this most people make use of the components from a condenser enlarger. However that requires a certain level of dedication and so most people, myself included, don’t do this and instead use an LED panel. It sounds like you probably wouldn’t be wanting to use a collimated light source either.
Depends where the abrasion comes from – if it is caused by the scanner, (I am ignorant about how Imacons work) they might not appear with repro scans. Does the Imacon uses transport wheels to move the 35mm film?
If the defects are on the film itself repro will naturally not remove them. And yes, retouching dust with repro is a pain. However, think about how happy you are not cleaning up 120 or even lager scanned surfaces.
Sorry
Errors courtesy iPhone, dictation