Direct answer
For the HP Smart Tank 7602, mark spacing and whether ink/toner is fused/dry identify media, roller, drum, fuser or maintenance faults. First, print a blank and patterned diagnostic page.
What this covers
- HP Smart Tank 7602 (28B98A)
- HP printer; Instant Ink eligibility, touchscreen, duplex, ADF and Dynamic Security behavior vary by model.
- The specific fault this record addresses: leaves smudges, spots or repeated marks
What it does not cover
- ×The same symptom on a different HP product line, which has its own record and its own cited source
- ×An on-screen error code whose meaning has not been checked against this exact model's manual
- ×Live electrical, gas, sealed-system, internal battery-cell or structural repair — a technician boundary, not a self-service step
Differential
What actually causes this, and how to tell them apart
These are ordered by how often each one is the answer, not by how easy it is to try. The point of the middle column is that two causes producing the same headline symptom rarely produce the same detail — that detail is what tells you which one you have before you change anything.
- 1
Ink has not dried before the sheet is handled
What separates it Smearing on heavy coverage or glossy media, worse when pages stack quickly.
How to confirm Set the correct paper type so the printer allows drying time, and let pages sit before stacking or handling.
- 2
A roller is contaminated and transferring residue
What separates it Marks in the same position on every page, repeating at a consistent interval.
How to confirm Measure the interval between repeats to identify which roller. Cleaning accessible rollers per the manual may resolve it.
- 3
The paper path is contaminated after a jam
What separates it Marks appearing immediately after clearing a paper jam or a spill.
How to confirm Fragments of torn paper or ink left in the path mark subsequent sheets. Inspect the path thoroughly.
- 4
The paper type setting does not match the media
What separates it Smudging on a specific paper only.
How to confirm The setting controls ink volume, drying time and fuser temperature, and a mismatch causes exactly this.
- 5
The printhead is contaminated with dried ink
What separates it Marks along the leading or trailing edge of every sheet.
How to confirm Run the printer's own printhead or roller cleaning routine rather than wiping the head by hand.
Before you touch a setting
Record this first — changing settings destroys the evidence
Every item below stops existing the moment a reset, re-pair or settings change is made. Written down first, they are what separates the causes above; recovered afterwards, they are guesswork.
- Whether the marks smear when rubbed — on a laser that indicates the toner is not being fused.
- Whether marks appear in the same position on every page, and at what measured interval.
- Whether it happens on all paper or one specific type.
- Whether it started after a jam was cleared.
Match the paper type setting to the media actually loaded
ReversibleIt controls ink volume, drying time and fuser temperature, and a mismatch produces exactly this.
Measure the interval between repeating marks
ReversibleIt identifies which roller is transferring residue.
Inspect the full paper path for fragments left after a jam
ReversibleTorn paper and ink residue in the path mark every subsequent sheet.
Run the printer's own cleaning routine rather than wiping components by hand
ReversibleHand-wiping a printhead or drum can cause permanent damage.
Model-specific
What is true of this model and not of its siblings
Generic advice for the product line fails here. Each item below is a property of this specific model family that changes which of the steps above apply to you.
- Model scope
- 28B98A. HP printer; Instant Ink eligibility, touchscreen, duplex, ADF and Dynamic Security behavior vary by model.
- Type — refillable INK TANK all-in-one
- A cartridge-free INK TANK inkjet AIO — you refill large ink BOTTLES into onboard tanks for a very low cost per page and thousands of pages per set. It is still inkjet, so the printhead can CLOG if unused; the savings come from bottle refills, not from being clog-proof.
- Initial charging & refills
- On first setup it 'charges' the printhead using a chunk of the starter ink (normal, not waste). Refill each colour bottle into the matching tank when low; do not run tanks fully dry, which can introduce air and cause clogs.
- Connectivity
- Wi-Fi/Ethernet/USB via HP Smart; 'offline' is usually a Wi-Fi drop or wrong queue.
- Symptom boundary
- This record covers HP Smart Tank 7602 when it leaves smudges, spots or repeated marks. A different symptom on the same hardware, or this symptom on a different HP product line, has its own record with its own causes and its own cited source.
Stop boundary
When this stops being a self-service repair
Continuing past any one of these costs more than the repair saves — in safety, in warranty, or in evidence a technician needs.
- !Never touch the drum surface of a laser printer or wipe it with cloth or solvent — fingerprints and scratches on a drum are permanent and show on every page.
- !Do not vacuum spilled toner with a household vacuum; the particles pass through most filters and into the motor.
Evidence ledger
Sources behind this answer
Visible sources support the visible claims. Home Product Support records the publisher, the fact used and the review date; community reports can suggest an issue but do not become a published fact on their own.
Where the manufacturer's article stops. HP Support publishes this as "Computer and printer support". Official HP serial/model lookup, drivers, diagnostics, manuals and repair support. What that article does not carry is the model boundary — it is written for a product line, and 28B98A is the scope applied here. Where a control label, terminal, indicator pattern or reset sequence differs on your unit, the manual for that exact model is the authority, not this page and not the article.
Exact questions
Common follow-ups
My HP Smart Tank 7602 prints faded even though the tanks have ink.+
Ink tanks are still inkjet, so a faded or streaked print with full tanks is a printhead clog — run the clean-printhead/nozzle-check cycle (repeat if needed) from the HP Smart app. Also make sure the tanks were not run completely dry (which lets air into the lines) and that the vent caps/seals are set correctly per the setup. If a colour is still missing after cleaning, the printhead may need a deeper clean. The tank system saves money on refills but does not make it clog-proof.
There's a mark in the same spot on every page.+
Measure the vertical distance between the repeats. Each roller in the paper path has its own circumference, so that spacing tells you which one is carrying the contamination. Clean whichever rollers the manual says are user-accessible; anything else is a service item.
Does this answer apply to every HP model?+
No. It is scoped to 28B98A. HP printer; Instant Ink eligibility, touchscreen, duplex, ADF and Dynamic Security behavior vary by model.
What should I record before troubleshooting smudges or spots?+
Record the complete model identifier, exact message or indicator, software/firmware where visible, the operating stage and what still works.
Why is a factory reset not the first step?+
A reset can erase accounts, networks, maps, schedules or preferences without distinguishing smudges, spots. The ordered checks preserve that evidence.
When should I stop and use qualified service?+
Avoid hot fuser areas and loose toner/ink contact.
Answer for the exact device and software version shown above.